Located at the confluence of the Eresma and Clamores rivers, the first written reference of its existence is in a Christian text dated to the twelfth century. The castle was built on a rock, which indicates its military origin and defensive use.

It served as the residence of King Alfonso VIII and was also where Isabel La Católica was appointed as the Queen of Spain.

 In 1764, King Carlos II established the Royal School of Artillery.

In the thirteenth century a Gothic-looking style was given to the building after restoration designed by the architects of Kings Juan II and Enrique IV.

The last restoration was in 1587 when the main courtyard and the honor school was redone by the architect Francisco de Morar,

The highlights of the Alcazar are the Arms Museum, the Tower of Homage, the Throne room, the Gallery room, the Pineapple hall, and the king's hall.