Most mountains on Hainan Island are 500 to 800 meters high, but 81 of its peaks are higher than 1,000 meters. Among those rising 1,500 meters or higher above sea level are Mount Wuzhi, Mount Yingge, Mount Ezong, Mount Houmi, Yajiada Ridge and Mount Diaoluo. These mountains mostly fall into three mountain ranges: the Wuzhi Mountain located in the central part of Hainan Island with its highest peak – ... the highest peak on the whole island – at an elevation of 1,867.1 meters; the Yingge Mountain lying northwest of Mt. Wuzhi with its highest peak at an elevation of 1,811.6 meters; and the Yajiada Mountain in the west of the island with its highest peak rising 1,519.1 meters above sea level. Most rivers on the island originated from the central mountainous area, forming a radiating river system. The inland has 154 streams flowing directly into the sea. The total drainage area covered by the three major rivers of Nandu, Changhua and Wanquan accounts for 47% of the island's territory.