Null Stern's hotel with no walls allows panoramic views of the Swiss Alps Guests are invited to sleep under the stars in this open-air hotel, which is located 6,463 feet above sea level in the mountains of Graubünden (+ slideshow). The Swiss Alps room has no walls, roof or bathroom – and is made up of only a bed with a couple of nightstands and lamps. However, Null Stern, the hotelier behind the concept, will provide a butler to deliver guests breakfast in bed, and a public bathroom is 10 minutes away. The room costs 250 Swiss francs (approximately £191) per night, and although it is bookable throughout spring and autumn, reservations can be cancelled at the last minute due to poor weather.