Lake Van is the largest lake in Turkey – but that isn’t its only claim to fame. Van Yüzüncü Yil University archaeologists and a team of divers recently discovered an underwater fortress there. The ancient nation of Urartu could have built the castle roughly around 3,000 years ago during the Iron Age.

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The team explored the lake based on local rumors of ancient ruins, despite other archaeologists familiar with the area telling them they probably wouldn’t find much. But the rumors turned out to be correct: diving team head Tahsin Ceylan told Turkey’s newswire service Andalou Agency the archaeological site is around one kilometer, or a little over half a mile, large. The fortress walls that they can see are between 10 to 13 feet in size.

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Some of the remains are loose piles of stones, others are smooth walls, according to National Geographic. Visual assessments led the team to estimate the underwater castle is around 3,000 years old. It would have been built when the lake’s water level was hundreds of meters lower. According to ScienceAlert, Lake Van’s water levels have fluctuated dramatically throughout the years.

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Urartu, a kingdom that flourished between the ninth and sixth centuries BCE, was centered around Lake Van, according to the Metropolitan Museum of Art. Other archaeological remains in the area, some higher than the current shoreline, are also the subject of study. And archaeologists and divers plan to return to the lake the learn more about the recently found sunken fortress. They’re not yet sure how deep the walls might be buried in lake floor sediment, and they hope to learn more about the people who inhabited the castle.

Via National Geographic and ScienceAlert

Images via National Geographic on YouTube