An expedition diver plunges into the waters of Lake Issyk-Kul to explore the underwater site of what is identified by researchers as a submerged medieval city in the settlement of Toru-Aygyr in Kyrgyzstan on September 22, 2026. Situated on an ancient trading route between China and Europe, little is known about the history of the settlement under Kyrgyzstan's largest lake or how it came to be flooded an estimated 800 years ago. The settlement is located at the heart of what was once the Silk Road, a trading route that linked China to the Mediterranean from the 2nd century BC until the mid-15th century. (Photo by Vyacheslav OSELEDKO / AFP via Getty Images)