Excavations suggest that it served as a tomb for about 80 individuals and that it dates back to the middle to end of the Neolithic period (4000-2500 BC).

Subsequent work by Vergílio Correia Pinto da Fonseca identified limited drawings on some stones.

Despite the destruction of the tomb, excavations have yielded numerous finds, including stone axes, flint tools and blades, flint arrowheads, club heads, pottery ceramics, clay vessels and objects of adornment.

[3][4][5] Apart from the visit by Da Fonseca, Ribeiro’s findings attracted little interest in the dolmen until the 1960s, when archaeologists became concerned about the possible destruction of the Antas de Belas as a result of urban expansion and highway construction.

In addition, the Anta do Monte Abrãao was threatened by the activity of a quarry located in its vicinity.