The National Jewelry Treasury

The underground vault of the Central Bank of Iran shelters an opulent array of priceless gems, crowns, and other jewels worn by the monarchs of the Safavid, Qajar, and Pahlavi dynasties. Must-sees in the dizzying collection include the Peacock Throne (a gem-studded daybed) and the 182-carat uncut pink diamond Darya-ye-Nur (Sea of Light). Limited openings and tight security mean you should plan your visit in advance, leave all of your belongings at reception, and keep your hands to yourself, lest you sound the piercing alarms.