Built on the site of the former Castle of Atouguia da Baleia, of which only a few vestiges remain, initial construction took place in 1557 and 1558 but there have been numerous subsequent modifications.

In the late 15th and early 16th centuries the area was the target of attacks by English, French and Barbary pirates, to which King Manuel I initially responded by installing four armed ships in Peniche.

In 1544, King John III recommended the construction of a castle on the peninsula and in the same year the most appropriate location to give protection to the town’s harbour was identified.

During the Spanish rule of Portugal (1581-1640), Philip II of Spain sent a military engineer to Peniche in 1589 to consolidate the fort and its walls and study possible improvements.

In the same year British troops, under the command of Francis Drake, began a march on Lisbon at Peniche, in an unsuccessful attempt to restore Portuguese sovereignty.

[3][4] In 1625 Philip IV of Spain highlighted the urgency of building a fort on the Berlengas islands, ten kilometres off the coast of Peniche, as these were often visited by corsairs.

Shortly afterwards an inspection report was prepared that commented negatively on its condition and in 1800 new batteries were built to make landing in the harbour more difficult and the parapet of the fortress facing the sea was also raised in height.

[7] In 1938 all buildings of the fortress were classified as a national monument, leading to some repair work being undertaken in subsequent years, in some cases making use of prisoners as labour.

On January 3, 1960, communist leaders Álvaro Cunhal, Francisco Martins Rodrigues and eight others connived with a member of the National Republican Guard who agreed to immobilize with chloroform a colleague responsible for the surveillance of the prisoners.

[1] From 1977 to the early 1980s, in the context of the process of Portuguese decolonization in Africa, parts of the fortress were used as temporary accommodation for families returning from the overseas territories.

After departure of the last returnees from the former colonies, a group of Peniche citizens, with the agreement of the City Council, developed a museum in the fortress dedicated to the anti-fascist resistance.

Improvements in 1984 made it possible to visit the cell where the secretary general of the Portuguese Communist Party, Álvaro Cunhal, had been held, as well as the location of his escape.