Shicheng City became China’s Atlantis, lost in 1959 when the government flooded the Xin’an River for hydropower. Fresh water ran through Han Dynasty-era archways, gates, homes and statues, creating 220-square-mile Qiandao Lake — and a modern legend. Rumors of its existence reached Leigh Chen in 2008. Inspired, the co-owner of the Shanghai-based Big Blue Diving created a team to explore the lake, located about five hours west by car from China’s largest city. After about a year-and-a-half of searching, “we almost gave up because visibility is poor,” says Chen.