Amazing visit just 50 minutes bus trip from downtown Madrid, with a lot of history. You cannot leave Spain without visiting it! Inside the building, you can admire excellent artwork from famous artists and painters of the XVI century. The only disadvantage is that you are not allowed to take pictures inside. I would recommend you use a tour guide as they have many options in multiple languages and provide you with lots of information. On a budget? Audio guides are a good just 3 Eur. There is a very impressive Library and Pantheon, with the marble sepulchers of former kings and queens you cannot miss. King Philip II and architect Bautista de Toledo did an astonishing job with this monument, considered one of the World Heritage sites. This is a good option for a one day tour, visiting the building, gardens, and having a good lunch just a short walk to one of the restaurants near to the site. This incredible attraction keeps a rating of 4.7/5.