Ba Be

Declared in 1992, Ba Bể protects Vietnam's largest natural freshwater lake, formed by the collapse of limestone karst caverns millions of years ago, ringed by wooded peaks and traditional villages of the Tày people, who still practise subsistence fishing and farming in stilt houses beside the lake. It is one of the last refuges in Vietnam of François' langur, an endangered primate of which fewer than 500 are thought to remain in the country.