The Castle of Espluga Calba, documented in 1148, stands in Lleida province as a remarkable example of medieval fortress evolution. Originally built as an advanced Arab fortress of the Siurana emirate, its church of Santa María was repurposed from a mosque during Islamic rule. After the Christian conquest, the castle belonged to the Order of the Hospitallers for four centuries, undergoing significant reforms in the 15th century under their administration. The current structure reflects this Hospitaller reconstruction, with later adaptations including conversion of the chapter house into a chapel. Today designated a cultural asset of national interest, the castle represents the layered history of Catalonian fortifications from medieval times through the modern era.
