Forte de Santana do Estreito, Colonial fortress in Estreito, Florianópolis, Brazil.

Forte de Santana do Estreito is a stone-and-lime masonry fort on a single terreplein, its parapet walls 1.20 meters thick and its plan an irregular hexagon. A single circular sentry box stands at the wall vertex watching the north bay channel. The one-storey buildings open onto the terreplein, where seven embrasures are set in brick.

In 1760, following orders from the Marquis of Pombal, Lieutenant-Colonel José Custódio de Sá e Faria surveyed the island's defences and proposed a battery on the point facing the mainland. The fort was built in 1763 during the government of Colonel Francisco Antônio Cardoso de Meneses e Sousa, to defend the Desterro anchorage in the strait. In 1793 the opposing Forte de São João do Estreito reinforced the position.

The weapons museum inside displays historical armaments from Santa Catarina's Military Police, reflecting how this location served as a defensive stronghold for the settlement. The collection reveals the connection between the structure and the region's security needs over time.

The fortress sits beneath Hercilio Luz Bridge on North Avenue and opens Tuesday through Sunday from 9 AM to 5 PM with free entry. Visitors can explore both the structure and the weapons museum housed inside without additional charges.

The fort was listed by IPHAN in 1938 and restored between 1969 and 1970, the first such work carried out on a fortification in Santa Catarina. Before that, it had been occupied by low-income families until 1969. Since 1975 an annex building has housed the Major Antônio de Lara Ribas Weapons Museum of the state Military Police.