Castle of los Duques de Alburquerque Monument · Mombeltrán, Arenas de San Pedro, Ávila Beltrán de la Cueva had it raised in the second half of the 15th century dominating the ravine: a rectangular plan with towers at the corners, an underground chapel and passageways. The second duke adapted it as a Renaissance residence and filled in the moat. Photo: Falk2 (CC BY-SA 4.0) What to see and do in Mombeltrán