The Yangtze River Delta or Yangtze Delta, also called Chang Jiang Delta, or the Golden Triangle of the Yangtze ), generally comprises the triangular-shaped territory of Shanghai, southern Jiangsu province and northern Zhejiang province of China. The area lies at the heart of the region traditionally called Jiangnan (literally, "south of the Yangtze River"). The Yangtze river drains into the East China Sea. In modern times the area is home to an economy the size of a medium-sized developed country, encompassing a GDP (when measured to purchasing power parity) of some $2 Trillion US, which is 21% of the national economy. The urban build-up in the area has given rise to the Yangtze Delta Metropolitan Area, the largest metropolitan area in China, with an area of 99600 km2, it is home to over 90 million people as of 2007, of which an estimated 50 million are urban.