“The Tubo Hotel is designed by T3arc Architecture and is a hotel where guests sleep in recycled concrete drainage pipes.  To keep construction costs low, drainage pipes that didn’t meet the required specs to be used as drainage pipes were bought and converted into hotel rooms.  To make better use of the available land, the concrete pipes were placed in a pyramid format, two at the bottom and one on top of them. Tubo Hotel, located in Tepoztlan, Mexico, just outside of Mexico City.”

http://www.unfinishedman.com/tubo-hotel-tepoztlan-mexico/

http://www.tubohotel.com/welcome/

http://www.youtube.com/watch?feature=player_detailpage&v=mKg9e-EkoPA