The Palacio Real is the official residence of the Spanish monarchy, though the royal family actually lives elsewhere — this one's for ceremonies and tourists. And what a building: over 3,000 rooms make it the largest functioning royal palace in Europe, bigger than Buckingham Palace or Versailles.
The interior is a procession of increasingly lavish state rooms spanning three centuries of royal taste, from Habsburg austerity to Bourbon excess. Don't skip the Royal Pharmacy, with its floor-to-ceiling shelves of porcelain jars, or the Royal Armory, one of the finest collections of historical weaponry anywhere. The throne room ceiling, painted by Tiepolo, is worth a stiff neck.
Closed on Mondays and during official state events. The Plaza de Oriente in front of the palace is a pleasant spot in its own right, lined with statues of Spanish monarchs.