From the surface, Turkey's Lake Van looks like any other large body of water. Turkey's largest, the lake sits in the far eastern region of the country, near Iran. The lake has a striking blue color and is a tourist attraction, benefiting towns around its rim. But below the surface lurks another town, which had hardly been seen in thousands of years.

During a recent dive to explore the lake, archaeologists from Van Yüzüncü Yil University and a team of independent divers found an underwater fortress.

In an interview with Turkey's newswire service Andalou Agency, head of the diving team Tahsin Ceylan recounted that other archaeologists familiar with the region told them they would find little in the water.

But the team proceeded with their research anyway, based on local rumors that ancient ruins were stashed beneath the water. (Was Noah's Ark found in Turkey?)

Speaking to local press, Ceylan said the archaeological site spans roughly a kilometer. The visible sections of the fortress's walls range in size from 10 to 13 feet.

Video shot by Ceylan shows the underwater archaeologists swimming through the turquoise blue lake. Large stones stacked together like a brick wall puncture the lake's waters. The fortress's remaining structures range from loose piles of stones to smooth square walls.

Based on visual assessments, the team estimates the remains are roughly 3,000 years old, meaning they may have been constructed during the region's Iron Age Urartian period.

Urartu was an ancient nation that spanned modern day Turkey, Armenia, and Iran. According to the Met's Department of Near Eastern Art, Lake Van was a hub for the ancient society. A rock inscription, the oldest documented Urartian record, can be found in Van.

The archaeologists believe rising lake levels slowly submerged parts of the city over time. Large village ruins from this period can also still be found around the lake's edges, above the current water level.