river in southern Vietnam that rises near Phum Daung, southeastern Cambodia, and flows south and south-southeast for about 140 miles (225 km). In its lower course it embraces Ho Chi Minh City (formerly Saigon) on the east and forms an estuary at the head of Ganh Rai Bay, an outlying part of the Mekong delta. The Saigon is joined 18 miles (29 km) northeast of Ho Chi Minh City by the Dong Nai River, an important stream of the central highlands, and just above Ho Chi Minh City it is joined by the Ben Cat River. At Cho Lon, the former Chinese southern sector of Ho Chi Minh City, it is joined by two ship channels, the Kinh Tau Hu and the Kinh Te. Ten miles (16 km) below Ho Chi Minh City is the oil harbour of Nha Be. Although it lies 45 miles (72 km) from the mouth of the river, the port of Ho Chi Minh City is the most important in Southeast Asia and is navigable to ships with drafts of up to 30 feet (9 m).