In the late 19th century, archaeologist Estácio da Veiga had revealed the archaeological importance of Rossio do Carmo. In the 1980s, an on-site excavation uncovered the structures of an old funerary basilica, which was occupied between the 5th and the 8th centuries, as well as dozens of graves from the same period and from the Islamic period (late 8th century-1st half of the 13th century).