Peñas de la Cerca is an Iron Age hillfort, in the province of Zamora, north-western Spain. It is near a hamlet called Rionegrito de Sanabria (municipio of Rosinos de la Requejada). Situated in a mountainous region on the north-western edge of the Northern Sub-Plateau, the site controls the middle of the Tera valley, between the natural shires of Sanabria (high and medium mountain) and Carballeda (plateau).
The site was excavated in two consecutive seasons in 2007 and 2008 by the PIDPAPZ project scientific team and supervised by the archaeologists Jose Carlos Sastre Blanco (University of Granada) and Oscar Rodriguez Monterrubio (UNED). Archaeological finds place this site in an intermediate period between the 1st and the 2nd Iron Age about the 7th century BC. It covers an area of around 2 hectares and settlement is distributed on tells, being the highest where a major number of dwelling structures and artefacts have been identified.
Defensive system
Excavations and surveys on the site have made possible the identification of several enclosures covering the north slope of the hill where the settlement was constructed. The inhabited zone was complex fortified area with two parallel walls (the internal and the external walls) and an interior highpoint surrounded by another wall (the top-hill wall). A line of more than seven tells (uninhabited) were constructed to alter the surface of the northern slope and to prevent a straight access to the inhabited nucleus, each tell is supported by a constructive wall creating a system of walled tells.
The excavation areas 1 and 4 unearthed the real structure of the walls: simple-faced walls with heterogeneous rough stone. This with a linear morphology and an enclosure adapted to the terrain sets the defensive system in Iron Age Chronologies. Without more accurate findings marking a concrete date, the chronology could cover an enormous gap of time similar to what happens in other northwestern Spanish hillforts belonging to the so-called Hillforts culture (Cultura Castreña)
Dwelling area
Excavation areas 2 and 3, on the second tell between the top-hill wall and the interior wall, had unearthed housing materials and structures related with three different periods of occupation of the settlement. The most ancient dwelling belongs to a period just before the 2nd Iron Age, so before the 6th century BC, because the level was discovered under pieces of metalworking clearly identified as materials from the transitional period between the 1st and the 2nd Iron Age. This first and the most ancient dwelling so far is defined by an ashen level where remains of wooden structures, grain store pits, plinth stones and a depot of burnt nuts (hazelnuts and acorns). An intermediate period of dwelling is located just above, this is the best studied and the most known period because it is the widest layer discovered so far. It is a hut-like structure with a uniform ground prepared to be dwelt and furnish with the basic Iron Age housing elements: Pit holes to support the structure, millstones, hand-mills, metalworking (bronze), remains of a bonfire, grain store pits and pieces of pottery. The chronology of this period is between the 6th century BC and the 2nd half to the 2nd Iron Age. More than 30 centimetres above, a third and more recent layer was discovered with a clear interruption in dwelling. This third and recent is belonging to the late 2nd Iron Age. This is a period identified by pieces of pottery but no structures were found in it. No Roman remains were found in the site so far so the settlement was probably abandoned (or not romanised) after the 1st century BC, in favour of other close sites as the gold mines of Los Corralones, Santo Toribio Hill or the valley of Vidriales (Eastwards into the plateau)