With 2800 rooms, the Royal palace of Madrid is the largest royal palace in Europe and on par with Versailles and Schonbrunn. It was built based on sketches for the Louvre in the mid 1700s and is filled with art, tapestries and state rooms, and hosts a Royal Armory and kitchen.
Hours: October-March: daily, 10-6; April-September: daily, 10-8.