It covers an area of 150 hectares. Exploring the underground city started in 1998. Given the 150-hectare area, we can safely say this is the biggest underground city of Iran and even the Middle East.
So far, two spaces of about 400 square meters have been explored in two stages. During the excavation, a number of pottery, bones, stone mortars and artifacts were discovered, and up to this stage of excavation, it’s obvious that the city dates back to the Seljuk period.
Down the wooden door to the underground city, there are about 15 steps in a curved way down, which leads to the first floor via a winding path, which is about 13 meters underground.
The other two floors, each, after passing through the corridors, leads to the next floor via a staircase. The underground city has proper ventilation, adequate oxygen and it’s very pleasant and cool inside.
According to the head of the excavation team, this is the biggest underground city of the world. Seyyed Mehdi Mousvainia said, “Even in Turkey, where it is said that 500 sites of handicrafts have been discovered and identified, there is no underground city of this size”.
Mousavinia added that full excavation of the underground city in Tafresh is impossible during “our lifetime”.