The town of Deba was originally set back from the sea, on the hill of Itziar. This settlement is documented as far back as the 11th century, and became a town on 24 June 1294, through a privilege granted by Sancho IV of Castile. Later, in 1343, the town was transferred from the hill to the Deba river mouth, next to the sea, retaining the same name, Monreal, and the same privileges.
This locality is home to Santa María la Real, a gothic church that was rebuilt in the 16th century. The church has a large bell-tower. The portico, naves and cloister belong to the first construction period, in the 14th and 15th centuries. The rest of the building is mainly from the 16th century. Inside, it has three naves of similar heights, separated by cylindrical columns marking out four sections and chapels between buttresses that correspond to different styles: gothic, flamboyant and Renaissance. The main altarpiece and the side altarpieces are baroque and the façade is completely solid with no openings except those for the bells, showing the building's nature as a fort and watchtower. In the lower part there are two arches that shelter the gothic entry and that still conserve remains of the 17th century polychrome work.
