Qinghai Lake
In 748, Geshu built Shenwei Base () upon Qinghai Lake, and Yinglong Castle () on an island in the lake itself, as defensive posts against Tufan. When Tufan attacked those outposts, he defeated them, and it was said that thereafter Tufan forces did not dare to come close to Qinghai Lake. In 749, he also recaptured Shibao Castle (石堡城, in modern Xining, Qinghai), which Wang had refused to attack earlier, leading to Dong's campaign. However, Yinglong Castle fell to Tufan after the Qinghai Lake froze, allowing Tufan forces to attack it over the ice.