Castillo de Balmaseda is a 13th-century fortress perched on a rocky outcrop overlooking the medieval town of Balmaseda in Bizkaia, Spain. This strategically important castle controlled the passage of commerce between Castile and the Basque coast, forming part of an integrated defensive system that included a central tower with walls descending the hillside slopes. Originally in use from the 14th to the mid-16th century, the castle saw renewed significance during the 19th-century Carlist Wars. Though largely in ruins and overgrown with vegetation, the site retains considerable historical and cultural value as a testament to the region's medieval past.
