Fort of São Lourenço do Bugio

Forte de São Lourenço is a fortress built on a sandbank in the Tagus River estuary, constructed with circular stone walls. Inside, barracks, storage rooms, a cistern, and a chapel once supported the daily life of the stationed garrison.

Construction started in 1590 under architect Giovanni Vicenzo Casale and finished in 1657 during King John IV's reign. This lengthy building period shows how important the location was for defending the coastline.

The fort represents Portuguese military engineering excellence, combining defensive capabilities with maritime navigation through its integrated lighthouse system.

This fortress sits isolated in the river, so reaching it requires a boat. Visitors should check tidal times and be prepared for limited access options.

The fortress stands on the only sandbar in the Tagus that stays above water year-round. This permanent dryness gave the site its name Cabeça Seca, meaning Dry Head.

Location: Oeiras e São Julião da Barra, Paço de Arcos e Caxias

GPS coordinates: 38.66049,-9.29919

Latest update: December 8, 2025 19:41