This unique 18th-century coastal castle, called del Cardenal, was built in honor of the Spanish Infante D. Luis de Borbón y Farnesio, brother of King Carlos III and sixth son of King Felipe V of Spain and Isabel de Farnesio, Duchess of Parma.

He was appointed Cardinal Archbishop of Toledo in 1735, Primate of Spain, Archbishop of Seville in 1741, and when he left the ecclesiastical state, he was appointed Count of Chinchón. He was an important patron who supported painters like Francisco Goya and Luis Paret.

This fort, along with the Prince's castle in CEE, was built between 1755-1757 to defend the port in the Ria de Corcubión.

The building is a fortified star-shaped peninsula built in stone from local quarries, which was a burden for the villagers who had to use carts and oxen to transport the stone to the castle.

With these construction features, the intention was for the piece to blend in with the surroundings and surprise attackers to protect expeditions heading to northern Europe or the Mediterranean, and to prevent looting of inland cities.

It has 17 gun ports and occupies an area of approximately 2,800 m2. Inside the enclosure, surrounding the courtyard, there is a U-shaped building that now serves as a residence but originally housed troops, warehouses, a gunpowder magazine, and other castle facilities. It had capacity for 96 men.

The interior is one floor with 3 stone bodies, including a kitchen, officers' quarters, weapon and gunpowder storage, all with barrel-vaulted ceilings and whitewashed walls. It also had vegetable gardens and a freshwater well for sustenance during a siege.

The fortress is in excellent conservation and faithfully respects its original structure.