Torre de Ruerrero is a late-medieval watchtower located in the municipality of Valderredible in southern Cantabria, built during the fourteenth to fifteenth centuries. The square-plan tower measures approximately 10.5 meters per side and reaches a height of 12–13 meters, featuring exceptionally thick walls exceeding two meters constructed from two layers of stone masonry with a rubble-filled chamber between them. Distinctive architectural elements include geminaded windows with semicircular arches on the southern facade and a truncated-cone tower attached to the northwest corner serving as a buttress. Remarkably, the tower was surrounded by a moat, of which significant remains measuring about three meters wide are still visible on the eastern side—an uncommon defensive feature for south Cantabria towers. Declared a Cultural Asset of Interest in 1992, the fortress likely belonged to either the Collegiate Church of Santa María de Elines or the Manrique de Lara lineage, serving as a strategic link between the castles of Bricia and Aguilar de Campoó.
