A wall made from schist slabs with a maximum width of 1.80 metres and a perimeter of 1,700 metres, associated with a ditch 5 metres wide and 1 metre deep, delimits this large enclosure. Later structures, such as a Roman wall and a property fence, were built on top of this prehistoric structure, reusing it. The inner enclosure, with a maximum diameter of 130 metres, was delimited by another wall 1.80 metres wide and a ditch 10 metres wide and 3.75 metres deep. Several hut structures were inside the large enclosure. The oldest structures were circular, made of intertwined branches covered in clay and with slabs of schist around the base containing the walls. The more recent ones, also circular, had stone walls with earthen elevations and diameters between 6 and 8 metres. Of the ten tombs identified outside the large enclosure, on its southwest side, one was excavated and revealed a tholos with a circular chamber and a small access corridor pointing east. There is another isolated monument to the east of the enclosure. Structures and burials from the Roman period, related to the neighbouring Roman site of El Pico, and from the medieval/modern period, linked to some hermitages, were identified at various points, documenting a prolonged use of the place throughout history.

A vast ditched enclosure, it has the particularity of associating ditches with robust walls. Such association is rare, the norm being that these two types of architecture do not coexist on the same site. In Portugal, this only occurs in the Monte da Ponte and Salgada enclosures (Évora district), but we don’t know if these structures operated simultaneously. At San Blás, however, this simultaneity seems evident.

Excavations in different sectors to minimise the impact of the Alqueva dam, which partially submerged the site.

Hurtado, Víctor (2004), El asentamiento fortificado de San Blas (Cheles, Badajoz). III milénio AC., Trabajos de Prehistoria, 61(1): 141-155.