Looming large above little Alburquerque is the intact Castillo de Luna. The centrepiece of a complex frontier defence system of forts, the castle was built on the site of its Muslim predecessor in the 13th century and subsequently expanded. From the top of the five-sided 15th-century defensive tower, views take in the Portuguese border (the Portuguese actually took the town for a few years in the early 18th century). You'll walk across the 10m-high drawbridge, then explore the grand castle digs.

Among many curiosities is a hole set in the wall of the defensive tower. It was used by the castle’s masters as a toilet – sending an unpleasant message to hostile forces below when under siege. Other gaps were used, similarly, for throwing boiling oil on enemies.

Visits are by guided tour in Spanish. An on-site Centro de Interpretación del Medievo (medieval interpretation centre) is due to open in August 2016.