Suzhou was the capital of the kingdom of Wu from the 12th to 4th centuries BC. Historically, it has been the origin of Wu culture, which later nurture the city of Shanghai. Today, Suzhou has become a core city of China's Yangtze River Delta economic zone, given its high GDP contribution to China. More recently, it has been a center of the silk trade and a place of gardens and canals. Suzhou has long been a heaven for scholars, artists, and skilled craftsmen, and this is still the case today.