Kunming is the capital and largest city in Yunnan Province, Southwest China. Known as Yunnan-Fu until the 1920s, today it is a prefecture-level city and the political, economic, communications and cultural centre of the province as well as the seat of the provincial government. The city is also home to several universities, museums, galleries and other important economic, cultural, and educational institutions. The headquarters of many of Yunnan's large businesses are in Kunming as well. It was important during World War II as a Chinese military center, American air base, and transport terminus for the Burma Road. Located in the middle of the Yunnan–Guizhou Plateau, Kunming is located at an altitude of 1,900 metres above sea level and at a latitude just north of the Tropic of Cancer. It covers an area of 21,473 square kilometres and its urban area covers 2,622 square kilometres. Kunming has population of 6,432,212, including 3,583,429 in the built-up area made up of 4 urban and 1 suburban districts, and is located at the northern edge of the large Lake Dian, surrounded by temples and lake-and-limestone hill landscapes.Kunming consists of an old, previously walled city, a modern commercial district, residential and university areas. The city has an astronomical observatory, and its institutions of higher learning include Yunnan University, Yunnan Normal University and a medical college. On the outskirts is a famed bronze temple, dating from the Ming dynasty.Its economic importance derives from its geographical position. Positioned near the border with Southeastern Asian countries, serving as a transportation hub in Southwest China, linking by rail to Vietnam and by road to Burma and Laos. This positioning also makes it an important trade center in this region of the nation. It also houses some manufacturing, chiefly copper, though some other chemicals, machinery, textiles, paper and cement take key. Though having a nearly 2,400 year history, its modern prosperity dates only from 1910, when the railway from Hanoi was built. The city has continued to develop rapidly under China's modernization efforts. Kunming's streets have widened while office buildings and housing projects develop at a fast pace. Kunming has been designated a special tourism center and as such sports a proliferation of high-rises and luxury hotels.