Sant Jordi d'Alfama’s Castle is a defense fortress built in the first half of the eighteenth century at one end of the Gulf of Sant Jordi.

The first attempt to build a fort in the area was a watchtower built in the twelfth century, and rebuilt as a fortress later in 1201 by the Templars, and established as the headquarters of the Order of Sant Jordi d'Alfama.

This fort was abandoned 1650, after being destroyed in a bombing by the Spanish galleys, so it couldn’t be occupied by French troops. There are still some foundations of this first fort near the beach.

The stones of the ancient fortress that did not break were utilized to construct the current strength, but in another location, a little further inland. This new maritime fort was built between 1732 and 1733 in order to monitor the sea lanes. It was built during the reign of Charles II.