The tower of Isola Rossa stands out on a rocky promontory near Trinità d’Agultu and, like the small town that developed in this area, is named after a large red granite rock surfacing offshore. This cylindrical, 11-metre-high tower was built entirely of red granite and is easily accessible by way of a small path that enables visitors to circumvent it and appreciate a stunning view, from Punta Li Canneddi in Isola Rossa to the island of Asinara. The only access is located 5 metres from the ground, while on top of the tower lies a terrace providing enough room for several people and a cannon.