The hidden faces of the stones

Very recently, in the slope of the same hill where is located the chalcolithic settlement of S. Pedro (Redondo, Évora, Portugal), we found a curious rock sancturay which closest paralel is, in the region, the Rocha da Mina site (see in this site, Caderno de Campo).
Very different, in terms of surrounding landscape, this monument shares the same features, carved in the rock.
No related artifacts have, so far, been found in the area.