It looms like a battleship in dry dock—matte gray and studded with porthole windows—along a not-so-lovely avenue in Jardins. It's also been compared to a slice of watermelon and Noah's ark. The Hotel Unique is one of the most jaw-dropping feats of architecture we've seen of late. Great slabs of glass and pale marble converge in the lobby, along with a quirky collection of baroque angels and colored glass bottles. The rooms are sublimely featureless except for that marvelous glass wall separating bed from bath—and, of course, those round windows. The building's idiosyncrasies work brilliantly: The floors in the suites along the outside walls curve up to meet the ceiling. On the roof is Skye, a hopping lounge centered around the swimming pool, which is lit up bloodred nightly for occasions like Coldplay's after party. From $380 to $4,000. At 4700 Avda. Brigadeiro Luís Antônio; 55-11/3055-4710; hotelunique.com.br.