El Puerto de Santa María is located on the banks of the Guadalete River about 10 km northeast of Cádiz, across the bay of Cádiz.

In 711, Arab from the North of Africa conquered southern Spain. They named the place Alcanatif which means Port of Salt, due to the old salt industry of Phoenicians and Romans. In 1260, Alfonso X of Castile conquered the city from the Moors and renamed it Santa María del Puerto.

This was one of the most importants towns of the Kingdom of Seville throughout the late middle ages. Christopher Columbus's first expedition to the Americas set sail from here. Later El Puerto was the residence of several wealthy merchants who operated Spain's trade with the Americas.

The Castillo de San Marcos was built from an Islamic mosque that was transformed into a fortified church after the Reconquista by Alfonso X of Castile