No charge. Free fitness at Baijia Lake Jingfeng Square, Shuanglong Avenue, Jiangning District, Nanjing. Nanjing, referred to as "Ning", was called Jinling and Jiankang in ancient times. It is the capital of Jiangsu, a sub-provincial city, a mega-city, the core city of Nanjing metropolitan area, and an important central city in eastern China determined by the State Council.