Bohai Bay is an inland sea in China, located between Liaoning, Hebei, Shandong, and Tianjin. It is a semi-enclosed continental shelf shallow sea. According to legend, Bohai Bay was once a flat expanse of land, and the Miaodao Islands were hilly terrain. Today, this body of water conceals a perplexing underwater image—a rectangular shape measuring approximately 24 kilometers in length and 20 kilometers in width, resembling an artificially constructed city with a meticulous layout oriented north to south.
While interpreting satellite images of Bohai Bay, scientists discovered an anomaly. The edges of this rectangular image perfectly align with the lines of latitude and longitude, suggesting it is not a natural phenomenon but rather a product of human activity. Some speculate that it could be the remains of an ancient city submerged beneath the sea or a military engineering project from the Russian Empire or Japanese occupation periods. Regardless of the case, this discovery has sparked a series of scientific inquiries into the formation of Bohai Bay, ancient geographical changes, and the development of Chinese social history.
Knowledge Link: The underwater topography of Bohai Bay is complex and diverse, with sediments primarily consisting of fine silt and mud. At the mouth of the Jiyun River, an underwater valley extends from the northwest to the southeast, disappearing in the central Bohai Sea. Bohai Bay has experienced multiple transgressions and regressions, with the last major transgression occurring around six to seven thousand years ago, a feat that ancient human technology could not have accomplished. Therefore, the origin of this underwater image remains an unsolved mystery.
