The Fort of Santa Catarina (in Portuguese: Forte de Santa Catarina, or sometimes Fortaleza de Santa Catarina de Ribamar) is in the municipality/concelho of Portimão in the Algarve in Portugal.
Map location:
On a height of land at the extreme east of Praia da Rocha, this fort defended the local settlements and the estuary of the Rio Arade, in conjunction with the Forte de São João do Arade on the opposite bank of the river in Ferragudo.
The fortification was ordered built during the reign of King Philip III (who was also King Philip IV of Spain). The site was already occupied by a shrine dedicated to Santa Catarina de Alexandria; inside the fort there still exists an early Gothic door from the shrine.
The fortification suffered major damage during the 1755 Earthquake.
Today the fort is used as a recreational site for tourists who stay in Praia da Rocha and the nearby marina of Portimão.