Located mid-way between downtown and the historic Belém district, this is the height of five-star luxury, a Belle Époque palace built by a marquess who made his fortune importing chocolate from cocoa plantations on the equatorial island of São Tomé. This is where the likes of Madonna, Cristiano Ronaldo, and Prince Albert of Monaco like to crash when they're in town. The pale yellow-and-white exterior looks simple enough, but inside it is a succession of ever more opulent salons filled with Louis XV furniture, gilt-framed oil paintings, crystal chandeliers, and windows bright with stained-glass nymphs. Built in 1905, the palace and its surrounding gardens (formal French out front, tropical exuberance round the back) are both protected national heritage sites. Most of the guest rooms are located in two modern wings overlooking the tropical garden, but there are four suites in the main palace, including the glorious Dom Carlos—named after Portugal's next-to-last king—which is bigger than some hotels. It's packed with antiques and features a unique African hardwood floor. The outdoor swimming pool is nestled amid the lush vegetation and looks like the sort of jungle watering hole where Tarzan and Jane would take a dip. Nearby are the award-winning spa and an oriental-themed summer house where lunch is served in season. For dinner, turn to the light-drenched Valle Flor restaurant, considered one of the best in the city, where you can settle in a room inspired by the Palace of Versailles and tuck into wild partridge in juniper brandy with foie-gras and chestnut purée, or baked Atlantic sea bass with crab sauce, baby sardines, and colored seaweed. If you can afford it, this is a unique place to stay.