This industrial-themed hotel, with locations in Germany and Austria, might be mistaken for a construction site at first glance. This is because the "rooms" are made out of giant concrete sections of pipe with coverings on both sides. The pipes are furnished with beds and lights and have interior murals. Though not luxurious by any definition, these rooms are definitely designed to provide a feeling of cozy comfort. And you certainly won't be able to beat the amount of privacy.