There a number of coastal watch towers in Menorca, dating from the 16th century. Then at the start of the 19th century, several Martello towers were built, for military purposes. One of the best preserved defence towers is the one in Fornells. It was built by the British between 1801 and 1802, to guard the mouth of the bay and to prevent, or at least delay, any enemy landings.

The truncated cone-shaped tower is built of stone and is reinforced with blocks of limestone. It consists of a water tank, a store room for food and ammunition, an upper level for the soldiers, and a flat roof for an artillery piece.

There is an exhibition in the tower describing the context in the early 19th century, enabling the visitor to understand the soldiers’ day to day life as well as the tower’s architectural features.