8. Salt



Palacio de Sal (Spanish for “Salt Palace”) is a hotel built from salt blocks. It is located at the edge of the Salar de Uyuni, the world's largest salt flat, 350 kms south of Bolivia's capital, La Paz.
 
The hotel walls are made of salt blocks stuck together with a cement-like substance made of salt and water. During rainy seasons, the walls are strengthened with new blocks, while the owners ask the guests to avoid licking the walls to prevent deterioration.

10. Wine Casks


 
Ever fall asleep alongside a good glass of French wine? How about inside a cask of a good French wine? The De Vrouwe van Stavoren Hotel in the Netherlands salvaged four wine casks from Switzerland and converted them into rooms.
 
Formerly filled with 14,500 liters of Beaujolais wine from a French chateau, each now holds a modest two-person room with standard amenities and even an attached bathroom and sitting room. Visitors from all around the world have traveled to the quaint northern port town of Stavoren to stay in one of these upcycled rooms. p78