The frequent incursions by French troops in the second half of the 17th century and the beginning of the 18th, revealed only too clearly the need, in this frontier territory, to have access to a military installation that could prevent the constant invasions from the neighbouring country. In 1751, during the reign of King Ferdinand VI of Spain, the decision was taken to build a military installation to be known as La Real Plaza de Guerra de San Fernando on the outskirts of Figueres. La Plaza was designed by the Commandant-in-Chief of the Corps of Engineers, Don Juan Martín Zermeño, to provide accommodation for five infantry batallions and five cavalry squadrons, making a total of 6,000 men and 500 horses. The building of La Plaza began in 1753, and the construction work continued into the early 19th century. At the time it was considered as a model of its kind, attracting notice for the vigour of its design and the magnificence of its conception. The 5 km. of moats, the 3.2 km. of perimeter wall, the 32.5 hectares of land occupied by the structure or the 9 million litres of water that can be stored inside its tanks are just some of the details that result in it being considered today as one of the biggest fortresses in the world, and the most important architectural monument in the Empurdà region.
Sant Ferran Castle