The Spa at the Mandarin Oriental
Prague, Czech Republic (mandarinoriental.com/prague)
Why it rules: It's the only spa in the world located in a former Renaissance monastery, yet is within proximity to pubs boasting Czech national treasure Pilsner Urquell.
Local flavor: The Linden Embrace treatment ($203), inspired by the healing linden tree, helps to "adjust your equilibrium" — aka relax you — via essential oils applied through heated poultices that are kneaded into tired muscles. Then a warm-blanket wrap and scalp massage lull you to sleep.