The ditch has a diameter of around 30m, a perimeter of 99m, a width that varies between 2 and 3m and an average depth of 1.55m. The materials collected in the ditch and pits correspond to fragments of ceramic containers, loom weights and faunal remains, with an equine skull in one of the pits. Delimited by a winding and patterned ditch, it is a small space with an entrance astronomically aligned with a significant point on the solar calendar (winter solstice). Such features point to ideological and cosmological concepts incorporated in its architecture. It is an example of the monumental and ceremonial enclosures with patterned winding ditches typical of the Guadiana basin, along with Santa Vitória and Rouca 7 in northern Alentejo (northern route), and the neighbouring Borralhos, Folha do Ouro and Monte da Laje (all in Serpa and part of the southern route), having been preserved on an island inside a water reservoir built as part of the Alqueva irrigation network.

The particularity here, unseen in any other ceremonial enclosure, is that the site is at the top of a small hill where there previously existed a necropolis of Neolithic hypogea surrounding a circular wooden monument (in the area of the current access gate to the reservoir). It is also where, after the enclosure, a necropolis of hypogea from the Bronze Age was installed (in the southwest corner of the reservoir). Thus, it forms part of the intermittent sequence of occupation of the Outeiro Alto hill between the Neolithic (3300-2900 BC) and the Full Bronze Age (2000-1500 BC), invariably with contexts with a pronounced ritual character, contributing to its status as a space of tradition and long-lasting rituality. A place with a distinct character, where a sense of ancestry and sacredness stands out, as well as the temporal depth of sacred spaces, whether through the material traces they show or through collective memories. And where the hill itself emerges as a sacralised element of the landscape.

Its identification and archaeological excavation occurred during the construction of a reservoir for the EDIA irrigation network (Alqueva project), after which it was preserved on an island within that reservoir.

Valera, A.C., Filipe, V. e Cabaço, N. (2013), “O recinto de fosso do Outeiro Alto 2 (Brinches, Serpa)”, Apontamentos de Arqueologia e Património, 9, Lisboa, Nia-Era, p.21-35.