It is acknowledged that the square shape results solely from interpretations by José Pires Gonçalves, a doctor and an amateur archaeologist from Reguengos de Monsaraz, previously responsible for identifying the nearby Menhir of Outeiro, who identified the stones as a cromlech in 1969, having been alerted to the existence of the central phallic stone by two local residents, José Cruz e Leonel Franco.

Originally raised and put into position by Gonçalves and others in 1972, they are arranged around a large phallic menhir, which is about 4.50 meters high and weighs 7 tons.

Seven menhirs, including the central one, are decorated with different motifs that show strong similarities to the designs identified in other monuments of the same type in the region, such as the better-known Almendres Cromlech.

[5] In 1998, as part of the efforts to minimize the impact on Portugal’s heritage resulting from the construction of the dam, Mário Varela Gomes of the New University of Lisbon (Universidade NOVA de Lisboa) excavated the site, identifying a diverse set of highly fragmented items, including lithic artefacts (trapezoids and flakes in silica, silicon shale, quartz and quartzite), and some fragments of ceramic containers, such as decorated cups.

The present location was chosen because of the availability of government land and the fact that there would also be room to build a planned archaeology museum, which remained unbuilt in 2023.