Fort Sao Julião da Barra is one of the largest and most powerful naval defense complexes in Portugal. The stronghold located in Sao Julião da Barra, on a promontory between two beaches, is the official residence of the Portuguese Ministry of Defense, as well as the largest Portuguese military center built in the Vauban style. The history of the fortress dates back to the 16th century, and its original task was to protect the Tagus River and Lisbon from a sea invasion.
Fort Sao Julião da Barra was built on the site of an ancient watchtower and its construction began in 1556. King of Portugal Jan III ordered the erection of a stronghold in order to further strengthen the mouth of the river in protection against invaders. The creators of the project focused primarily on the defensive functions of the stronghold, ignoring the aesthetic value. The building built of gray stone and masonry plaster is, however, a building of great historical importance.
For many years, the fortress served as a political prison. Currently, only part of the rooms are open to the public, because the entire fortress is managed by the Portuguese Department of Defense. Still, it is worth visiting the fort Sao Julião da Barra, which remains an example of the largest defensive center in the country.