Iranian archaeologists have discovered a massive three-story city in central Iran, probably dating from the ancient or Islamic eras.

During the first season of excavation, a team of archaeologists, architects and history and geography experts have managed to unearth the outlines of a city of labyrinth-like architectural structures, 2.5 meters under the topmost layer of the earth, in the central city of NoushAbad, near Kashan. They have discovered, indeed, three layers of urban constructs, said Zahra Sarokhani, head of the researchers.

“The first story is 2.5 meters deep, while the third layer is 16 m deep. The height of each story is 1.8 m,” she added. “It is unprecedented in our excavation history to dig out such a place, arguably making it unique in the whole world. The city can lead us to learn many things about this style of architecture.”

The underground city has corridors, rooms and other architectural structures, all interconnected to the upper or under level with flights of stairways. Archaeologists speculate it was built during the ancient or Islamic eras, though they have no wild guess about the exact area of the city due to their limited excavation works so far.

Kashan is an oasis city lying in a desert at the eastern foot of the Central Iranian Range. Kashan was earlier an important station on an important caravan route between Kerman and Isfahan. Kashan has several ancient monuments. Most famous are the mausoleum of Shah Abbas the Great, the 12th century Friday Mosque and the Safavid royal buildings southwest of the city centre.