The building is located on a rocky outcrop at a height of 50 metres, overlooking the sea of the Golfo degli Angeli. It takes its name from the Grotta del Diavolo, located on the cliff below. It was built the late 1500s under the Spanish Empire.

Its task was to guard the surrounding coastline and the cave below, so called because pirates used to stop there. The strategic importance of the site was due to the wide outlook it gave from Capo Sant'Elia to the beaches of Chia.

The structure is mainly composed of two parts: the first is a cylindrical body leaning against the rock and above it a truncated cone-shaped tower. It has a height of 14.30 metres and a diameter of 5.86 metres. Its circumference measures 18.40 metres. Volcanic rocks and andesite were used as raw material for its construction, embellished by calcareous sandstone ornaments.

The inner chamber was very small, with a diameter of 3 metres, vaulted in the shape of a dome in which there was a hole to climb up to the terrace. The corbels of the sentry box defending the entrance and the banks of the threshold in white sandstone can be seen in the structure. During the 1600s the garrison consisted of two soldiers, while in the 1700s it was reduced to one soldier.

From its summit, one can see the towers of the Pula territory such as those of San Macario and Coltellazzo and others of the Sarroch territory such as those of Zavorra and Antigori.