10 kilometers to the southwest from the Spanish city of Valladolid is a small town of Simancas. The city is known for the fact that in the late 10th century there occurred a large-scale battle in which the combined forces of Castile, Leon and Navarre defeated the Moorish army, thereby forcing the Arabs to flee to the South.

In the 15th century Simancas Spanish kings erected a castle on the site of an old Muslim defensive buildings. Under king Carlos I, the fortress was turned into a prison for prisoners. From 1540 in the walls of one of the towers of the castle on the orders of Charles V was used as an archive, containing the basic documents of the Spanish Kingdom. Under king Philip II, under the custody of the documents was given to the entire castle and reorganized in connection with the needs of the Main archive. For storing documents, was appointed archivist, who supported all papers are in order. The main archive of the Kingdom is a unique collection of historical documents, among which were Sundry expenses books, urban registries, land registries, city ordinances, privileges and more. To date, the archive has about 33 million of various documents, about 400 thousand of them are the works of the Holy Inquisition.

The castle itself is a massive Bastion structure, built of light stone. In the facade of the building is highlighted with crenellated towers, the roof is made of the material of dark color contrasting with the color of the building. The main tower that adorns the building, topped with a beautiful high dome, made in the Baroque style.