The main vestibule is made of stone... walls, floors, decorations. There is a statue of Carlos III who initiated the construction of the palace. The main staircase leads you to e first level where you are allowed to see many of the "State" rooms. Unfortunately, no picture taking allowed. I can tell you that MY favourite rooms were the Hall of Columns, e Porcelain Room, the Banqueting Hall, the Chapel, and the Stradivarius Room. Why is the latter included? Why, even years after not playing the violin, I was aching to hear how one of the two in the room sounded. I would have settled for the viola or one of the two violin cellos though... Even though I couldn't hear them, they were still gorgeous to look at.