[3] The islands isolation also provided ideal conditions for the monks to live in austerity through solitude and silence, assiduous prayer and healthy penance.

[2][3] The fort was also used during the Liberal Wars, serving as a forward base for troops loyal to Pedro IV of Portugal, to attack the fortress of Peniche (then occupied by Miguelist forces).

[2][3] The DGEMN Direcção-Geral dos Edifícios e Monumentos Nacionais (Directorate-General of Buildings and National Monuments) became involved after 1981 in the restoration of the structure, culminating in projects between 1986 and 1987 to consolidate the fortification and make it secure for visitors.

The fort is located in the waters off the southeastern coast of Berlenga Grande, on a small islet connected to the island by a causeway/arch-bridge and anchorage to the north.

[2][3] The two-storey walls serve as both defense and narrow enclosed corridors that circuit its perimeter, broken by several arched windows on the northern and western facades.