You should not leave Madrid without knowing this impressive National Heritage monument and UNESCO Heritage since 1984. Built between 1563 and 1584 the monastery covers an area of just over three hectares (33,327 m²).
If your budget is small or you do not have enough to see all the museums and historical monuments you want, you can consult this guide of the Hotel Miau so you can plan the visits that will not cost you anything ... and if you go early you can be the first in the row, avoiding long queues.
Do not miss the opportunity to see the Royal Guard wearing his uniform, similar to the one used by the Spanish army in the time of Alfonso XIII, in red, blue and white. The relays, solemn and ordinary, link the current Royal Guard with its historical background.