This castle-turned museum is an old fortress built during the 17th-18th century to defend the port of Palma. It was completed in 1762 with a building of a low battery on the cliff to strengthen the defense for the port.
In 1981, it became a military museum, refurbished, and opened in 1991. It has a room for temporary exhibits, a conference room and an audio visual room for events and cultural activities.
The castle museum has magnificent panoramic views of the sea, the Bay of Palma and towns nearby. It also became as a hospital, officer's prison and battery of salvo in the previous years.
The name San Carlos was used because the vice roy at the time of the first attempts to build it was Don Carlos Coloma, Marquis of Espinar.
