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 of the white-headed langur, reckoned one of the most threatened primates in the world, with a total population below 100 animals restricted to a single limestone island in Vietnam.