Santa Catalina, Cádiz
Building began in 1596 after English and Dutch pirates, privateers, whatever, sacked the city.
Cádiz is almost entirely surrounded by water. It was named ‘Gadir’ by the Phoencians, who founded their trading post in 1100 BC, which means that Cádiz is the oldest city in the Western World.
It was later controlled by the Carthaginians, and then the Romans.
During the Napoleonic War it was at one point the only place in Spain to resist Napoleon’s army.
The castle is now a museum and cultural centre.