The Trypillia (Russian Tripolye) mega-sites in the Kirovograd and Cherkassy regions of Ukraine constitute the largest sites in fourth millennium BC Europe (Videiko 2004). Discovered in the 1970s, aerial photography and geophysical prospection were used to produce plans of these sites in what has been termed 'the first mega-site methodological revolution' (Videiko 2012). The five largest mega-sites are Taljanky (340ha), Nebelivka (260ha), Dobrovody (250ha), Tomashivka (220ha) and Maydanetskoe (200ha) (Videiko 2012). At Taljanky, over 2000 structures have been documented by geophysical prospection and excavation (Burdo et al. 2012). The resulting population estimates, together with an apparent three-level settlement hierarchy (Ellis 1984), imply the possibility of state-level societies contemporary with Uruk developments in Iraq. The rationale, origins and collapse of these large sites, however, has remained unclear, as has their impact on the local environment and their place in local and regional settlement structures.
These research questions led to the establishment of collaboration between Durham University and the Kyiv Institute of Archaeology in 2009. Current support from the Arts & Humanities Research Council (AHRC) is providing funds for a four-year, interdisciplinary project (2012–16) focusing on the Trypillia phase BII mega-site of Nebelivka, dated to the early fourth millennium BC (Chapman & Videiko 2011) (Figures 1 & 2). A key goal of the project was the creation of a plan of the mega-site, using modern geophysical prospection methods, as the basis both for an understanding of social space at Nebelivka and as a sampling strategy for the creation of internal site phasing. Without knowing the numbers of coevally occupied houses through the settlement sequence, we cannot fully understand mega-site dwelling processes.
The implications of modern geophysical results have been termed 'the second mega-site methodological revolution' (Chapman et al. in press). At Nebelivka, the Durham team used Bartington Grad 601-2 dual sensor fluxgate gradiometers to cover a total area of 286ha over 4 visits totalling 38 person-weeks. The vast majority of anomalies relate to burnt, partly burnt or unburnt structures, as well as soil-filled pits and ditches. Given the absence of overlapping house-floors, the principal data-processing issue was the removal of the strong magnetic signal from the Ukrainian 'granite shield'. Prospection extended beyond the outer circuit wherever possible, to ensure that all associated features were included in the survey.
The high-resolution plot (Figure 2) shows the features of a typical mega-site plan structured around two concentric circuits of houses, with mostly empty space between the circuits, almost 50 internal radial streets, a scatter of features outside the outer circuit, enclosed within a boundary ditch, and an apparently 'empty' core area. The settlement within the boundary ditch covers an area of 238ha, and includes over 1200 structures, many large pits often associated with structures, several ditches and two palaeo- channels. Many weaker anomalies almost certainly reflect unburnt houses, typically on the radial streets. The external ditch, of an estimated 4m width and a cored depth of 2.5m, is particularly visible around the north, west and south-west sides (Figure 3), present on the south side but hardly visible on the east side as a result of tree cover. A fundamental structuring principle concerns the positioning of some 15 pairs of unusually large structures near the circuits, with one structure located between the circuits and the other placed either inside or outside the circuits (Figures 3 & 4). There are also cases of single large structures (Figure 4). The extrapolation of the results of the 2012 excavation of one such 'mega-structure' suggests the presence of public buildings for meetings or ceremonies, acting as focal points for several clusters of houses. One such pair was placed on the axis of a major break in both circuits, although there are few examples of aligned breaks in both circuits.
The layout of the two circuits shows both segmentation and irregularity, ranging from groups of closely-set structures which perhaps shared walls (Figure 5), through small groups of parallel structures (Figures 4 & 6), to widely spaced structures with perhaps more individual than group identity (Figures 4 & 6). Such a layout suggests the notion of an 'ideal design' whose variable implementation followed more or less successful pathways. Gaps between house groups were also regularly reinforced with additional features, whether ditches, linear pits or lines of pits. This segmentation led to multiple deviations from the planning 'ideal' of a single continuous circuit. The most striking deviation related to the course of a pre-existing palaeo-channel (Figure 5) but there are six dog-legs in the inner circuit and perhaps three in the outer circuit (Figure 3)—only one relates to an existing topographical feature. A striking form of variability concerns the distance between the two circuits—from 70m to 150m—showing that concentricity was achieved over only 30 per cent of the plan.
The distribution of inner radial streets shows a 'busy' north-west zone and a 'quiet' south-west area (Figure 2) but the maximum distance between radial streets of 250m shows a discontinuous pattern. The composition of the streets shows as much variability as that of the circuits, including at least three layouts which resemble open public spaces (Figure 6). It is noticeable that, even in the streets, there were groups of structures, separated by gaps of up to 50m. Some of the longer groupings may have represented 'primary' streets, between which later streets were added.
The completion of an entire mega-site plan with modern geophysical methods is a breakthrough in Trypillian archaeology, defining a new research agenda for the next decades. Many of the individual features (pits, unburnt houses, house-pits, ditches) are ripe for future excavation, with the prospect of genuinely novel information. The most important result reported here is the emergence of distinct groups of structures, which can be interpreted as 'neighbourhoods', enabling us to study Trypillia people in the size of groups most relevant to them rather than only at the level of a massive settlement.
Grateful thanks to Durham University and the Kyiv Institute of Archaeology for project support; thanks for financial support to the AHRC for Research Grant AH/I025867, National Geographic Society (Grant 2012/211) and the British Academy for Small Research Grant SG54204; and thanks to the Kirovograd, Novoarkhangelsk and Nebelivka authorities for support, the geophysics teams for their enthusiasm and Janine Watson and Linda Bosveld for her illustrations.
* Author for correspondence.