The Sant Nicolau Castle is strategically located at the entrance of the Ciutadella port. This tower was a defence point built by order of the Sapniards at the end of the 18th century due to the many attacks by sea the island suffered in the past.

It has a the shape of a pointless pyramid, with an octagonal base and it is built of mares (stone extracted from the island’ quarry). A moat protects its perimeter which also outstands for the beautiful baroque statues decorating the façade.

The inside of the castle is dome shaped and was where the live stock and arms were kept, and as a garrison for the soldiers. A spiral staircase communicates with the foof floor and with a turret used as an watch point. The roof top was the attacking area and the watch point and the cannons are situated at the entrance of the castle.

The Sant Nicolau Castle forms part of the many military defence turrets scattered around the Minorcan coast line built during the Spanish, French and British occupations between the 17th and 19th century. The current owner is the Ciutadella Council and it can be visited free of charge.