When we think of salt, we think of it as a seasoning. But for an Iranian restaurant group, salt was the main material for a new kind of eco-friendly building. The “Salt” Restaurant of Shiraz is located in the southern Iran, where the walls, tables and even the stairs were covered with a salty coating. To our surprise, this layer of salt helps clean the polluted air of the city. Inspired by local and naturally occurring salt caves of the region, the group wanted to create a design that reflected the area’s distinctive salt mines and Marharloo salt lake of Shiraz. They stated, “In this particular case, the walls, structural…