Castro Hotel Syros

A nine-room luxury boutique hotel tucked into a 19th-century Italian merchant's mansion in Ermoupolis, Syros's capital. The original stone vaults now house a wine bar, while a hammam, gym, and indoor jacuzzi round out the amenities, which is quietly remarkable at this scale. Syros draws fewer tourists than the big-name islands, which means the Castro's guests tend to feel like they've discovered something, which, to be fair, they have.