The reason why this city is called Noushabad (meaning the city of cold tasty water) is because in the ancient times one of the Sassanian kings who were passing through this area stopped here to drink water from a well and he found this water extremely clear and cold. Therefore he ordered to build a city around this well and name it Anoushabad which eventually turned into Noushabad.

This underground city is located under the ancient city of Noosh Abad 7 kilometers from Kashan. Noosh Abad was built during the Sassanid era. One of the commanders of this dynasty, passing through this region of Iran, found it pleasant and ordered the construction of a village that later became a city.

This underground city also dates back to the Sassanid period, about 1400 years ago (the beginning of Islam). It was built by hand and was intended to protect the inhabitants of the city of Noosh Abad from foreign aggression. It was used at the time of the Seljuk, Safavid and Qadjar dynasties before disappearing under the floods. In 1381 (2002), it was discovered accidentally and since then, it is the place of visit of the Iranian and foreign tourists.

OUYI was built horizontally and vertically on three or more floors. The latter are connected by wells which served at the same time for the circulation of air in the floors and in the rooms. The first floor is 3 meters deep and two more floors at 8 and 16 meters deep. The illumination of this city was done with animal fat burning in special earthen containers arranged in holes dug in the walls of corridors and halls.
Up to now, about 50 rooms have been found in this underground city, some resting places for the guards, and some toilets. The height of the galleries is between 170 cm and 180 cm and can be easily circulated. The entrances to this city were numerous and were in busy places such as bazaars, mosques, qanats, etc. so that people can protect themselves in case of threat. It could hold about 3000 people. The entrances were clogged up after the inhabitants had passed so that for years they remained hidden.
No building material was used for the construction of this city. Only a few picks that had to be used to dig the canals and wells were discovered.
So far, only 500 meters of first floor corridors have been prepared for the tourists' visit. The other floors are not visitable because they are not yet secure. Due to the existence of different wells and canals, the area is estimated at several thousand meters.

According to some accounts, this underground city would be connected by a series of qanates to the city of Niyasar and more precisely to the Niyasar cave about forty kilometers away.

Ali Pirayandeh, director of the cultural and tourist heritage of the city council of Noosh Abad, specified that the city of Noosh Abad, located on the north-south route of the country, was very often attacked by different foreign tribes over the centuries, and it is for this reason that the inhabitants of this city built this great underground city to protect themselves from external aggression.

the underground city of Ouyi (Noush Abad) in the northern Kashan - Isfahan province - is considered one of the masterpieces of ancient architecture. as Noushabad city is located in the region of central desert of Iran, its weather is quite harsh. during the day Noushabad has a very hot temperature and during the nights it gets pretty cold.