The Portuguese fortress stands on the eastern part of Diu Island. The citadel is protected by the sea on three sides and on the land side by a deep moat cut through the solid sandstone rock. The original fortification constructed under Nuno-da-Cunha in 1535 was rebuilt by Dom Joao de Castro after 1546 A.D. An imposing double line of bastions facing the city protects the castle on the west side. There are three of them on the outer line and four on the inner, named after Christian saints. The bastion of Saint Luzia is formed on the extreme point of the castle on the east. Buildings like the Governor’s palace, prison and barracks for the garrison besides several Churches and cisterns etc. are located inside the fort.