Formed more than 200 million years by three big tributary lakes: Pe Lam, Pe Lu and Pe Leng, Ba Be now covers around 500 hectares, 178m above sea level. It is 17-23 m deep, and even 29m at some points.

At the World Freshwater Lake meeting held in the US in 1995, Ba Be was listed among 20 freshwater lakes that need protection.

In 1997, Vietnam asked UNESCO to recognise Ba Be as a world heritage site and in 2004 it became an ASEAN heritage park.

In 2011, Ba Be received a UNESCO certificate recognising it as Vietnam's third Ramsar site – designated wetlands of international importance.