|Villages like Tongli were the basis of much of the wealth of the Jiangnan region. While the Yangtse served as a natural barrier between the north and south with its wide rushing waters, the smaller streams and rivers served to connect villages with easy transportation in the delta region. Where larger rivers met, villages grew into major trading centers such as Suzhou. Smaller villages developed along the streams, with as little a mile between them. They traded among themselves and used the larger trading centers to trade with more distant regions.