"The undisputed grande-dame hotel of Madrid—based on a clever idea King Alfonso XIII had just before World War I—faces Plaza Neptuno’s fountains and one of the world’s seriously great art museums, El Prado. Whether you stay here or not, save time for a cocktail in La Rotonda lobby bar beneath the famous stained-glass cupola. And have a wander around the hotel’s small museum, which reveals its life over the past century, name-dropping Hemingway, Picasso, the Rolling Stones, and Dalí, who was fond of doodling on the walls. Bedrooms are defined by a restrained, Belle Epoque elegance, with the brand’s signature focus on wellbeing—super-food ingredients on the room-service menus, white-tea-scented bathroom bottles, staff-led jogging paths—and beds that will swallow you up whole."