The underground city of Ouyi, also known as Noushabad Underground City, lies 5 kilometers north of Kashan in Iran’s Isfahan province. The city of Noushabad, one of the oldest cities in Iran, is famous for the existence of a hidden city carved beneath the desert surface. The ancient enigmatic town of Ouyi at Noushabad is not only an architectural wonder but also a testament to the strategic acumen of its ancient inhabitants throughout the history of Iran.

Underground City of Ouyi

What has come to be known as the underground city of Ouyi is a complex of dense and extensive structures such as nested narrow corridors and small-sized rooms dug under the city of Noushabad and expanded to the current level of the city. The depth of Ouyi ranges from 4 to 16 meters. Local residents believe the underground city extends beyond the historical city walls, covering an estimated area of 4 kilometers. This underground labyrinth was created by hand as a set of rooms, corridors, wells and numerous channels spread across three floors. On the walls of this city, you can see the distinctive marks of sharp tools. Given the hardness of the soil in this region, archaeologists theorize that the tools used for digging had diamond-like properties.

On August 8, 2005, the underground city of Ouyi in Noushabad was registered in the list of national monuments of Iran, receiving the registration number 15816.

Ouyi Underground City, Noushabad, Kashan, Iran 

History of Noushabad 

Most of the experts believe that the origin of the Ouyi city dates back to the Sasanian Empire era – considered one of the Sassanid capitals under King Khosrow I. However, what is clear is that the underground city of Noushabad served as a residence for tribes and people in different periods. The name “Noushabad,” meaning “city of cold tasty water,” stems from a legend involving a Sassanian king who discovered refreshingly cold water spring in the area and ordered a city to be built around the well. It is said that during the Mongol invasion of Persia, the city served various strategic purposes, especially as a refuge. Many details of the city have been lost due to floods and the passage of time; But some pottery has been found that dates back to 1500 years ago. You can also see works from the Safavid Empire to the Qajar era.

The underground city in Noushabad was discovered in 1983 by a person who was digging a well in his house. 2 years later it was registered in the list of national monuments of the country.

Noushabad’s Location

Located in the central desert region of Iran, Noushabad experiences extreme temperatures—scorching hot days and freezing nights. This harsh climate likely contributed to the development of the underground city as a haven from both environmental and human threats. The underground network allowed inhabitants to escape the daytime heat and provided protection during raids.

Noushabad’s Layout 

The primary reason for the construction of Noushabad’s underground city was security. During periods of unrest and frequent raids, the subterranean network provided a safe haven for the city’s inhabitants.

Noushabad’s underground city of Ouyi spans depths ranging from 4 to 18 meters and features a complex network of tunnels and chambers. The city has three distinct levels, designed to enhance defense. Moving between levels involves navigating curvy passages, making it difficult for intruders to advance. Additionally, the architecture includes several defensive mechanisms, such as hidden traps and rotating stones. On the first floor, there are many corridors – designed in a winding way – in which they could easily hide and run away from potential pursuers. Sometimes the corridors are too short.

The second and third floors of the underground city are also designed in such a way that in the past they used it as a shelter. It seems that food was also stored in these floors.

The lighting of this city is attractive. On the wall we can see the place where the tallow burner was placed. We can assume that the hallways were always lit.

They had also thought about air circulation and air conditioning. U-shaped channels or wells do the work of ventilation. In addition, it has benefited from the difference in air pressure.

Structural Features

Levels and Depth: The underground city comprises three levels, with depth varying to optimize defense.
Passages and Rooms: Curved passages and small rooms create a labyrinthine layout that confuses invaders.
Defensive Mechanisms: Features like deep holes covered by rotating stones were used to trap enemies.
Ventilation System: Vertical wells and U-shaped channels ensure adequate airflow throughout the complex.
Entrances: The city had multiple entrances, some originally hidden within homes and public spaces.

Noushabad’s Fast Facts 

• Noushabad’s underground city was rediscovered in 2006 by a resident digging a well.
• It is a a notable example of handmade architecture in the world
• The underground city of Ouyi dates back to 1500 years ago
• It is known as the largest underground city in the world
• The area of ​​this city is estimated to be more than 15 thousand square meters
• This complex has many entrances, but some of them have been destroyed and blocked due to floods.
• Most parts of the underground city of Ouyi have a height of about 180 cm and a person can easily pass through it.