The [Palacio de Sal in Bolvia](http://www.palaciodesal.com.bo/) is one of the most unique hotels in the world. What makes it so unique is the fact that the entire hotel is made from salt. It is located in the heart of Salar de Uyuni which happens to be the biggest salt plain the world. You’ve got to see it for yourself to believe it. Oh, and don’t even think of licking the walls. It’s forbidden!