Antiga Igreja de São João Batista, Porto

Forte de São João Baptista is the fortress whose bastions dominate the Douro mouth and guard Porto’s river approach. Its story begins with a church and an abbot’s residence commissioned here by Dom Miguel da Silva; together with the nearby São Miguel-o-Anjo Lighthouse, they marked the arrival of Renaissance building in northern Portugal. Work on the fort began in 1570, under King Sebastian, from a design by fortification master Simão de Ruão.

During rebuilding in 1646, the old church was demolished, and its uncovered nave and chancel became the fort’s parade ground. The heavy walls turn this historic religious site into a military enclosure. The fort later served as a political prison, holding 227 Jesuits in 1759.

In 1808, a Portuguese flag raised here became Portugal’s opening act of resistance to Napoleonic occupation. The fort now houses the National Defense Institute.