The fascinating Underground City of Nooshabad is situated 8 kilometers to the north of Kashan in Isfahan. It is one of the most remarkable underground cities that has ever been created by human’s hand. This ancient shelter was completely unknown until a decade ago when a local resident was digging a ditch in his home. This 1500-year-old underground shelter covers a broad area and it consists of tunnels with many twist and turns along with canals, food storages, traps, chambers, staircase and air ducts. According to the stories, the name of this city came from the ancient time when one of the Sassanian kings were passing by this city and drank water from one of the wells, the water was so soft and cool that he named the city Nooshabad, meaning “city of cold tasty water”. Later on the king ordered to build the underground city. Initially, the city was constructed to tolerate the overwhelming heat of the desert, however the main reason was to stay save from foreign invasions. In addition, historical evidences prove that the underground city was mainly used as a shelter during the Mongol invasion in 13 century. This shelter was made in such a way that inhabitants could live there for several days. Nooshabd underground city, also known as Ouyi by locals, is now open to tourists.