Kau Keng Shan (Chinese: 九逕山) is a hill in Tuen Mun, New Territories, Hong Kong and stands opposite from Castle Peak. Kau Keng Shan has a height of 507 metres. During the Ming dynasty, the area around the hill was used as a defense position against foreign forces, especially the Portuguese, who had occupied Tuen Mun from 1514 to 1521.