Tower with a truncated conical body on a visible circular plinth (base) two meters high. Total height of 17.90 meters. Built of squared ashlar masonry, with a battered (sloping) profile. It has a single elevated entrance, originally accessible by an external staircase (a section of a masonry staircase remains up to a platform 3.7m high). Inside, it has a double superimposed chamber, separated by a dome, and a spiral staircase leading to the upper chamber and the sentry box accessing the terrace/rooftop. The terrace is protected by a parapet with some merlons. It preserves engravings of marine fauna on the original interior plaster. Its function was to watch the coast and the mouth of the Guadiana against pirate attacks and to defend the border with Portugal. With the natural silting of the Guadiana's mouth, the tower moved away from the coastline, losing its main defensive function and serving only as a watchtower from the mid-18th century.