A defunct sewage system is posing a fatal threat to an ancient three-story underground city in Noush Abad, near the central Iranian city of Kashan.

“The local people have dug out wells to dump their sewage and now not only the whole city of Noushabad is floating on sewage, but also the leakage is threatening a newly-discovered underground city, bearing relics from the Sasanid dynasty (226-651) to the Safavid era (1501-1722),” said Zahra Sarokhani, head of the research team.

She called on municipality officials to build a new sewage system as soon as possible because the leakage has damaged some walls and provided a habitat for pests, estimating the project would require over $500,000 of public funds.

The city features labyrinth-like architectural structures, starting 2.5 meters under the surface and running 18 meters deep. Noush Abad residents had been reporting about underground corridors and chambers when they were digging wells in their yards for sewage, since most Iranian cities lack a sewage network.

Working on the tip-off, archaeologists started digging the area, but to their chagrin, they failed to find any clue, until during the second week of excavation, an 18-year-old digger by the name of Ali Reza Khabbazi did finally discovered something that turned out to be an underground city, whose three stories are interconnected by several flights of stairs.

Next year the research team intends to ask sociologists and anthropologists for help to determine the lifestyle of the inhabitants.