Incredibly cool, the 149-room, eco-friendly 25hours Hotel Bikini Berlin is a great option for hip, design-conscious travelers looking to stay in the heart of the city. Its West Berlin location is next to Berlin Zoo and very close to Tiergarten and Breitscheidplatz, with plenty of places to dine and drink within walking distance in the neighborhood. This design hotel's theme is urban jungle, and its huge public spaces are full of greenery, glass, and exposed pipes. There are two restaurants and a bakery on-site, plus a rooftop cocktail bar overlooking the zoo. There's also a 24-hour fitness center, a sauna, and a lounge space for relaxing. Rooms are just as quirky and trendy as the rest of the four-pearl hotel, with doodles drawn on the walls, hammocks, and rainfall showerheads in the minimalist bathrooms.