Archaeologists in Kyrgyzstan have discovered the remains of a drowned medieval city that was once a Silk Road hotspot.

A medieval city that has been swallowed by a large salt lake was discovered by archaeologists in Kyrgyzstan, as a result of a joint effort between Russian and Kyrgyz scientists.

An international underwater archaeological expedition of the RGS, the Institute of Archeology of the RAS, and the Institute of History, Archeology, and Ethnology of the National Academy of Sciences of the Kyrgyz Republic took place in the northwestern waters of Lake Issyk-Kul.

The now-submerged city was deemed an important stop on one of the Silk Roads on a route between China and the West during Medieval times, archaeologists said. The city itself was believed to be hit by a major earthquake in the 15th century, leading to it sinking beneath water level.  

The drowned city was uncovered while researchers explored various submerged sites in the lake. The body of water was located high in the Tian Shan mountains near Kyrgyzstan's border with Kazakhstan, a statement from the Russian Geographical Society noted.

This came as a result of archaeologists surveying four sections of the lake at a depth of 1 to 4 meters (3 and 13 feet), leading to the discovery of buildings made of bricks and remains of destroyed structures with stone. Part of a pair of millstones, historically used for grinding grain into flour, was uncovered. Additionally, parts of architecture with exterior decoration, believed to be used for social reasons, was uncovered. This led archaeologists to believe the location was used as a mosque or a bathhouse, amongst other theories.

The reason for believing this space was used as a mosque due to its proximity to Toru-Aygyr, a mainly Muslim settlement in the Middle Ages.

Other ruins were made of stone with wooden beams, which would not have occurred naturally underwater.

According to the Russian Geographical Society, samples from their findings have been sent for further analysis.

Lake Issyk-Kul is one of the world’s deepest lakes with some parts reaching 700 meters (2,300 feet) below surface, according to the Kyrgyzstan government. There is no river outlet and is not fully saltwater nor freshwater — mildly salty.

"The monument under study is a city or a large commercial agglomeration on one of the important sections of the Silk Road," said archaeologist Valerii Kolchenko, the head of the Kyrgyzstan contingent of researchers on the expedition, in the statement.

"At the beginning of the 15th century, as a result of a terrible earthquake, the city went under the waters of the lake … the tragedy can be compared to Pompeii."

Amongst the discoveries in the now-submerged city were a mill for grain, archaeologists said. Upon finding remains in a cemetery, the remains of two of the deceased had their faces looking toward Mecca, now Saudi Arabia, which is still common practice in burials in the Muslim faith.

The exterior decorations of the remaining public structure also led archaeologists to believe it could have been an Islamic school, also known as a madrassa.

Archaeologists dated the cemetery back to the 13th century, around when Islam was introduced to the region by rulers of the land, much of Central Asia, from the 1240s to 1502, the statement added.

Additional burials were found nearby, and were not believed to be a non-Islamic cemetery.

Before being ruled by “the Golden Horde,” a Mongol state believed to be ruling the region at the time, it was ruled from the 10th century by the Karakhanids, a Turkic dynasty centered on Kyrgyzstan, the statement said.

Maksim Menshikov, the leader of the expedition from the Institute of Archaeology of the Russian Academy of Sciences, Toru-Aygyr was a multicultural city when it was founded before the 13th century. "People here practiced various religions: pagan Tengrianism, Buddhism, Nestorian Christianity," he said in a statement. Introducing Islam changed the core of the city, he added, noting that people preferred trading with other Muslims.

The sunken city also revealed many pieces of medieval Muslim pottery.