Introduction

1The Spanish Northern Meseta is a geographical region of about 95,000 square kilometres located in the Iberian Peninsula. It consists of large sedimentary plains and limestone plateaus of the Upper and Middle Duero and Upper Ebro Basins, and it is limited by three powerful mountain chains at north (Cantabrian), east (Iberian) and south (Central System), and a deep river canyon at west (‘Los Arribes’). Until the last quarter of the 20^th century the scholars considered this area poor and backward during Late Prehistory due to the absence of archaeological remains comparable to other peninsular examples such as the Mediterranean Cardial Neolithic or Copper Age cultures like Los Millares or Vila Nova de São Pedro. Nowadays this assumption should be reconsidered. In the case of the Early Neolithic, there are numerous 6^th millennium cal BC sites that accounts for domesticated animals, cereal grains and farming stone tools. During the 3^rd millennium cal BC, in the Copper Age, walled or ditched settlements, stone huts, and the complete chaîne-opératoire of metallurgical production appeared. However, it must be said that the economic intensification and the amount of labour invested in the political economy recorded in the Northern Meseta does not reach the levels known for the southern Iberian Copper Age.

2Besides this, regarding the megalithic phenomenon it has been suggested an undergoing revolution. Forty years ago, almost all the known monumental tombs were limited to the southwestern area of this territory (Morán Bardón 1931, 1935). However, since the 1970’s intensive surveys and excavations have recorded and characterized along the entire region this prehistoric manifestation (fig. 1). Archaeological excavations in Salamanca Province (Delibes de Castro & Santonja Gomez 1986), Middle Duero (Delibes de Castro et al. 1987), Las Loras of Burgos Province (Delibes de Castro et al. 1993), Carpurias mountain chain surroundings (Palomino Lázaro 1990) or Ambrona Valley (Rojo Guerra et al. 2010) have served to define the characteristics of this funerary expression. It shares the same basic principles with the Atlantic Iberia megalithism, but it also shows some particular manifestations, namely the ‘redondil’ type tomb (Delibes de Castro 1996) or ‘San Martín–El Miradero’ spatula-idols (Delibes de Castro et al.2012).

1. Distribution of megalithic tombs in the Spanish Northern Meseta

3Thanks to these researches we count on a fairly well-defined chronological sequence. The farmers and herders who colonize this territory in the mid 6^th millennium cal BC (Delibes de Castro & Fernández Manzano 2000, Estremera Portela 2003: 209, Rojo Guerra et al. 2008: 357) are the same who began to scatter the Meseta with these funerary monuments at the end of the 5^th millennium cal BC (Delibes de Castro & Rojo Guerra 1997). The ‘megalithic’ is the only known funerary use employed between then and c. 3000 cal BC¹. Only with the arrival of the 3^rd millennium cal BC the individual pit burial becomes more extended during a great wave of changes that includes population growth, more sedentary habitats, new land colonization and the adoption technological innovations such as secondary products exploitation and metallurgy. Even in these new times the sepulchral use of old megaliths –but not new megaliths construction – survived in some areas, as a clear evidence of the significance that they previously had.

Late Neolithic population dynamics

4The lack of contemporary habitats to the building and first use of the neolithic monumental tombs represent one of the biggest archaeographical gaps in the Prehistory of this region. Nevertheless some sites can be related to this moment due to some radiocarbon dates. There are samples dated in different moments during the 4^th millennium cal BC from the oldest phase of El Abrigo de Cueva Rubia (Pérez Rodriguez 1989) and from the ‘Structure 1’ of La Revilla del Campo (Rojo Guerra et al. 2008: 34), to which it can be added those from the vast sedimentary sequences of the caves of La Vaquera (Estremera Portela 2003), El Mirador (Vergès Bosch et al. 2008) and El Portalón (Ortega et al. 2008).

5There are some another open-air sites that can be ascribed to these moments throughout the characteristics of the contained material culture. During the 4^th millennium cal BC Early Neolithic-like microliths and Copper Age-like arrowheads with flat-over retouch coexisted and the decorative motifs made on the Early Neolithic pottery were gradually abandoned and substituted by plain ceramic. Following these type-fossils it is possible to assign some domestic sites to the Late Neolithic. Some of them such as La Nava-Rehoyo, El Carrascal or La Perrona are located in areas not occupied during the Early Neolithic (Villalobos García, in preparation).

6Besides, it should be noted that the limited archaeological visibility of this chrono-typological horizon is determined by the small size of these habitats. Many of the Late Neolithic sites identified are nothing but larger Copper Age settlements in which the existence of a previous occupation phase may be stated due to some materials from previous chronological periods. Otherwise, smaller Late Neolithic sites have also been documented in the surrounding area of some megalithic tombs as the result of intensive field-walking surveys, but these field works have never achieved any solid evidence of Late Neolithic large-scale settlements (Delibes de Castro et al. 1997, 2011). All of these indicators suggest that during the Early and Late Neolithic the Spanish Northern Meseta widely hosted a dispersed, occasional and itinerant population dynamic (Delibes de Castro & Zapatero Magdaleno 1996, Delibes de Castro et al. 1997, 2011, Díaz-Guardamino Uribe 1997, Rojo Guerra et al. 2008: 347, Marcos Saíz & Díez Fernández-Lomana 2009).

7Regarding the subsistence practices, we can only count on the analyses of pollen, seeds, charcoal, etc. of the sedimentary sequences of the aforementioned caves. With this evidence, it can be said that the cultivation of cereals is asserted during both Early and Late Neolithic, but that it was during the second period when it is noticed an increase of legumes together with and a decrease of the forest (López García et al. 2003, Allué Martí & Euba Rementeria 2008, Ortega et al. 2008, Vergès Bosch et al. 2008, Martínez-Pillado et al. 2010). All of these works agree that during the 4^th millennium cal BC there is a more intense human impact on the environment.

8So, the evidence known of the Late Neolithic economic practices suggest that they were people who did not live in large and permanent villages but whose subsistence economy relied in part on farming fields. The occupation of new lands, the increase in the use of legumes and the reduction of forests can be seen as the consequence of demographic growth and population pressure. Therefore, these people probably exploited some lands and moved off after periods of few years in a territory that hosted more groups as the time passed.

The diversity of the megalithic architecture

9During this period between the late 5^th millennium and c. 3000 cal BC – the Late Neolithic – an intense and complex activity of megaliths construction took place in the Northern Meseta, as can be seen in the different varieties of architecture documented (fig. 2).

2. Floor plants of the different megalithic types

10The simplest type is the collective burial covered with a basic earth mound – Los Lastros (Palomino Lázaro 1990) – or a cairn – El Cementerio de Los Moros (Benito Delgado 1892), Rebolledo (Delibes de Castro & Rojo Guerra 1997). Another model is the one that includes a simple chamber without corridor. It could be a cist type – Nava Alta (Delibes de Castro et al. 1993) – an open round chamber – Pedro Toro (Leisner & Schubart 1964) – or a closed one – San Adrián (Palomino Lázaro 1990). These simple chambers are structured with big stone slabs, however examples in which other construction materials have been used are also known. For instance, in the case of El Guijo, one large slab is combined with little stone blocks (Díaz-Guardamino Uribe 1997). There are also monumental tombs made out exclusively with small stone blocks. They were probably roofed with a corbelled vault like a tholos², as in the case of La Peña de la Abuela or La Sima (Rojo Guerra et al. 2010).

11Despite this architectural variety, it should be noted that the most widely accepted type is the passage grave: two thirds of the monumental tombs of the Northern Meseta are passage graves. The most outstanding examples are Las Arnillas (Delibes de Castro et al. 1986), El Torrejón de Villarmayor (Arias 1989) or El Prado de las Cruces (Fabián García 1997). Very big slabs define a round chamber – probably roofed with vegetal material – and a southeast-facing corridor sometimes lintelled. It is not rare to document a circle of smaller orthostats disposed around the camera as a structural reinforcement of the mound. The Late Neolithic people of the Northern Meseta developed a new kind of tomb from the passage grave type, the so-called ‘redondil’. In this case, as can be seen in Los Zumacales (Delibes de Castro et al. 1987) and La Velilla (Zapatero Magdaleno 1991), the chamber orthostats are not placed in vertical position, but they appear horizontally facing down on their bigger surface.

12As for the chronological framing of the different types of monumental tombs, it should be emphasized that the passage grave type has been adopted sometime after the adoption of the megalithic phenomenon. Charcoal samples recovered inside the chambers of Rebolledo and Fuentepecina II indicate that they were already in use during the last quarter of the 5^th millennium cal BC (Delibes de Castro & Rojo Guerra 1997). Other sites, like Fuentepecina III and IV (Delibes de Castro & Rojo Guerra 2002) and the aforementioned El Cementerio de los Moros or Los Lastros can be traced back to these initial moments trough their grave goods chrono-typological characteristics. All these archaic tombs are earth mounds, cairns or small chambers without corridor. But instead, samples coming from levels under the mounds of many passage graves indicate they were not built before later moments, some of them even in the 4^th millennium cal BC (Delibes de Castro & Rojo Guerra 1997) (fig. 3).

13The issue of megalithic architectural evolution from simple to complex forms in Iberia is still open to debate (e.g. Jorge 1989: 412, Bueno Ramirez 1994), but it has been suggested that a typological development towards the long passage grave could have took place in some areas of the Northern Meseta (Delibes de Castro et al. 1992, Delibes de Castro 1995, 2010, Delibes de Castro & Rojo Guerra 1997, 2002). However, despite the fact that neolithic tholoi – La Sima phase II –, simple chambers – El Guijo – or cairns – El Silo – are still being constructed and used in the region after the first third of the 4^th millennium cal BC (Rojo Guerra et al. 2005: 106, Moreno Gallo et al. 2010-2012), the later emergence of passage graves and its major adoption suggest that this architectural type has been imposed gradually to the detriment of the other options. This evolution indicates the success of an open-tomb type that offers greater possibilities for the development of other activities apart of the purely funeral ones.

The megalithic ritual practices

14Some years ago G. Delibes de Castro stated that the megalithic phenomenon of the Northern Meseta is characterized by a ‘structural pluralism’ but it certainly shows a clear ‘ritual homogeneity’ (Delibes de Castro 1995). All the architectural types were monumental tombs built in order to host collective burials. In the case of many megaliths, however, there is strong evidence showing that, beyond the obvious sepulchral function, other non-strictly funerary activities took place. The presence of ritual acts performed in domestic Neolithic contexts such as offerings probably related to the innovative farming practices (Villalobos García s. p.) demonstrates that the megalith was not the only arena which hosted ceremonial activities. Nevertheless, the collective burials of diachronic use allow establishing a close relationship with the ‘world of ancestors’ which would affect all the activities developed here legitimizing its intent and strengthening its significance. We agree with the idea that these tombs were not exclusively designed for the ancestors worship (Waterman & Thomas 2011), but we also think that the symbolic presence of them would be something inevitable.

15The most basic example of non-strictly funerary activities at the megalithic arena is the manipulation of the human remains stored inside the chambers, where it is usual to find the bones forming a mixed ossuary. In many cases, this situation may be the consequence of post-Neolithic looting and reuse, even though examples of randomly mixed ossuaries from neolithic intact levels are common, as exemplified by Las Arnillas (Delibes de Castro et al. 1986: 15) or La Velilla (Delibes de Castro & Zapatero Magdaleno 1996). In some cases it can be noted how some sets of bones were intentionally grouped. A ‘nest of skulls’ and a pile of femurs were documented respectively in Las Arnillas and San Quirce (Delibes de Castro et al. 1993: 26 and 86). In La Sima phase II the ossuary was gathered in bundles of skulls and long bones that group the remains of several individuals (Rojo Guerra et al. 2005: 161-167). These examples could respond to a simple functional reorganization in order to free up space for new burials. However, the processing of human bones – used for making a dagger in Las Arnillas (Delibes de Castro et al. 1986), a spatula-idol in Los Zumacales (Delibes de Castro & Paz Fernández (de) 2000) or an unidentified tool in La Tarayuela (Rojo Guerra et al. 2005: 203) – shows that the treatment of the ossuaries was more than functional. In addition, there is evidence in the Northern Meseta of human bones in Neolithic and Copper Age domestic sites that suggest the existence of some kind of traffic with relics (Delibes de Castro et al. 1999). Furthermore, there is an indicative example of a human bone fragment found in a pit from the domestic site of La Revilla del Campo. This context has been dated in the second third of the 4^th millennium cal BC (Rojo Guerra et al. 2008: 213 and 376), the same period when the phase II of La Sima – an open tholos found at less than 2 km away – is dated (Rojo Guerra et al. 2005: 106). Therefore, all these archaeological documents – ossuary manipulations and traffic with relics – emphasize the importance that the skeletal remains placed inside the megalithic tombs had for the neolithic religious practices in the Northern Meseta (figs. 4.1, 4.3 & 4.4).

16There are cases of huge amounts of vessels dated in the end of Late Neolithic / beginning of the Copper Age from inside the chambers of megaliths of the southwestern part of the Northern Meseta (Delibes de Castro & Santonja Gomez 1986: 172). In the case of El Miradero, located in the Middle Duero, there appeared small ‘fungimorphic’ bottles (Guerra et al. 2009: 276) (fig. 4.2). The presence of those vessels inside the megalith chambers could be seen as offerings or, maybe, as the result of some kind of feasts.

4. Some evidence of ritual acts inside megalithic tombs

17The reiterate presence of burned soil and ashes in about twenty tombs from the Northern Meseta must be also mentioned (Benito Delgado 1892, Morán Bardón 1931, 1935, Delibes de Castro & Santonja Gomez 1986, Delibes de Castro & Rojo Guerra 1997, Fabián 1997, Estremera & Fabián García 2002, Delibes de Castro 2010). So many examples and other testimonies such as a fireplace found inside La Casa de los Moros passage grave (Palomino Lázaro 1990) can rule out the hypothesis that these findings are the result of mere accidental causes. As well as the rearrangements of ossuary, it might be said that the use of fire would have been a functional procedure for creating space for new inhumations. However, the spectacular traces of fire closure documented in several tombs suggest that in many cases its use would obey other intentions. The abundant ashes found in Los Morcales demonstrate that a prolonged fire took place (Rojo Guerra et al. 2002). More impressive is the case of the so-called ‘lime-kiln tombs’. The thick quicklime crusts covering the sepulchral level in El Miradero (Delibes de Castro et al. 1987), La Peña de la Abuela and La Sima gave rise to an interesting hypothesis that argues that a great fire caused the pyrolysis of the chamber limestone blocks (Rojo Guerra et al. 2010). An experimental construction of one of these tombs and its subsequent fire indicates that this is possible after 20 tonnes of combustible plants and 35 hours of continuous fire (Rojo Guerra et al. 2010). It clears any doubt about the intent of such closure ceremony and opens the door to accept the idea of the common use of fire in the megalithic rituals.

18Another issue regarding the activities connected with these monuments is that of the architectural remodelling and restructuring. The clearest example is La Sima. In this site a first phase of lime-kiln tomb is followed by a second phase of tholos and even a third one in Bell Beaker times (Rojo Guerra et al. 2010). Other sites show smaller changes. The mound of El Moreco was enlarged after its construction (Delibes de Castro & Rojo Guerra 2002). The corridors of La Ermita de Galisancho and La Torrecilla de Terradillos were added to the original building sometime after the construction (Delibes de Castro & Santonja Gomez 1986: 114). Some changes inside the chamber have also been documented in other tombs, for example a pit excavated inside the passage grave of Galisancho (Delibes de Castro & Santonja Gomez 1986: 73). In opposition, a completely different conduct is shown in the evident closure procedures found in some other tombs. A layer of pebbles up to a meter thick covered the chamber of Los Castillos de Villar de Argañán, El Castillo de Castro Enríquez and La Torrecilla de Terradillos (Morán Bardón 1931: 41 & 45, 1935: 6). A similar event took place in the case of the corridors of El Moreco, La Nava Negra, Valdemuriel (Delibes de Castro et al. 1993: 26), El Prado de la Nava (Benet Jordana et al. 1997) or El Turrumbero de la Cañada (Palomino Lázaro et al. 2006). These remodellings are the proof that the monumental tombs were not merely receptacle for the dead, but a monument of recurrent usage that should be maintained, restored and/or sealed according to the events and needs.

19We can link to a previous paragraph of this article when warning that is in the passage grave type where almost all the non-strictly funerary practices took place. For this situation, it may be thought that one of the reasons that favoured the gradual widespread acceptance of this architectural type may be the adaptation of the funerary structure to these ceremonies. Also, the subsequent addition of corridors could show the material representation of this need that enablesan increased communication between the ‘living’ and the ‘dead’ (Sherratt 1990). Based on all this evidence, we believe that the megalithic tombs of the Northern Meseta, especially the passage graves, had a key role as arena of many different activities, some of them undoubtedly transcendental, which set the monumental tombs as the main ritual and religious centres for the Late Neolithic communities.

Conclusions

20Many scholars have considered the European megalithic phenomenon as a process of land marking (e.g. Renfrew 1976, Sherratt 1990, Bradley 1993). This hypothesis has also been employed in the case of the Spanish Northern Meseta (Delibes de Castro & Santonja Gomez 1986: 136, Rojo Guerra 1990, Delibes de Castro et al. 1997, Delibes de Castro & Rojo Guerra 2002).

21Concerning the relationship between megalithism and the population dynamics, it should be emphasized the spatial overlap identified between megalithic tombs and other structures or domestic-type activities. Some pits and flimsy huts have been documented under a series of tombs such as La Velilla (Delibes de Castro & Zapatero Magdaleno 1996), El Teso del Oro (Palomino Lázaro & Rojo Guerra 1997), La Peña de la Abuela (Rojo Guerra et al. 2010) or Los Zumacales (Delibes de Castro & Herrán Martínez 2007). It must be accepted that La Peña de la Abuela tomb was built over a previous domestic sitea thousand years after being abandoned (Rojo Guerra et al. 2008: 208-212), but the structures under the mounds in La Velilla or Los Zumacales were dated inc. 4000 cal BC, contemporary with the first passage graves. In addition, there are more indirect testimonies of this relationship between the daily life and the tombs. The cereal pollen found under the mound of El Moreco passage grave (Delibes de Castro 2000) represents the ‘fossilization’ of the agricultural practices developed in their surroundings at the time of its construction. As well, the absolute dating of a campfire near Rebolledo cairn indicates the development of some type of activity beside the tomb during the Late Neolithic but after its construction (Delibes de Castro & Rojo Guerra 1997).

22All these data demonstrates that the megalithic tombs were not built in remote and savage ereas. They were fully integrated into the daily life of the Late Neolithic people. It was argued previously that this period was characterized by an itinerant, occasional and recurrent population dynamic. Therefore, it is very likely that in areas such as La Lora (Rojo Guerra 1990), Valdavia Valley (Delibes de Castro & Zapatero Magdaleno 1996), Ambrona Valley (Rojo Guerra et al. 2005, 2008) or Avellanosa-Susinos plateau (Moreno Gallo et al. 2010) megalithic tombs and other monuments like standing stones were used to structure, by the strength and durability of the stone, the relationship between these people with the land.

23It has been also argued that the megalithic tombs would have fulfilled other functions such as arena for non-strictly funerary ritual activities (Jorge 1989, Sherratt 1990, García Sanjuán 2009, Bueno Ramirez & Barroso Bermejo 2010). The use of fire, the manipulation and traffic with human remains and, possibly, the celebration of feast-type ceremonies make the megaliths of the Northern Meseta, besides the role of simple receptacle of the dead and the main articulating element of the population system, the basic centre of Late Neolithic ritual activity. In our opinion, these actions counted on the indispensable presence of the ancestors as strengthener of the ideological guideline of permanence and stability that the megalith offered. The frequent architectonic remodelling would demonstrate the long continuity over time of these practices.

24To sum up, considering the vital importance of these funerary monuments on basic aspects such as the settlement dynamics and the ritualism, we defend that they probably hosted a very important part of the political life. There is strong evidence in the Northern Meseta that supports the emergence of some kind of social inequality and political hierarchy during the Late Neolithic. The most obviously is the great size of many tombs. Some of them must have required a lot of labour investment, like as the 24.000 man-hours expended in the construction of the mound of El Torrejón de Villarmayor (González López & Teijeiro López 1999). Obviously, someone or some group must have assembled a specific amount of social power to organize such enterprise. But there is more evidence. The access to be buried in the monumental tombs was restricted to specific people (Delibes de Castro 1995). Although they were collective burials there are cases of individualized grave goods (Guerra Doce et al. 2009) and segregated spaces inside some tombs (Rojo Guerra et al. 2005). There are ornaments made in exotic material coming from more than one hundred kilometres away such as marine shells, variscite, muscovite, talc, lignite or slate (Guerra Doce et al. 2009, Villalobos García 2012).

25In this context, it is inevitable that the privileged ones would have developed an ideology to justify the inequality and try to convey the whole community through public ceremonies (Shanks & Tilley 1982, Earle 1997: 155, García Sanjuán 2011). These acts would find their ideal arena in the megaliths. The fact that arrowheads, blades and axes were found as grave goods in repeated occasions indicates the acceptance of a patterned equipment (fig. 5) that could make reference to the ideological figure of ‘the warrior’ (Guilaine & Zammit 2002: 176). This individual would have also exhibited lavish and exclusive objects – ‘San Martín-El Miradero’ spatula-idols (Delibes de Castro et al. 2012), ornaments made of exotic materials (Guerra Doce et al. 2009, Villalobos García 2012) or special stone axes (Villalobos García s. p.) – in a series of acts of statement of power. These events would have their logical epilogue at the time of death when these emerging leaders dressed up and fully-equipped, as well as some of their relatives and supporters, enjoyed the privilege of being buried inside the megalithic monuments.

5. Patterned grave goods