As the Luang Prabang-based kingdom began to spread, it stepped into Vang Vieng, settling “Muang Song” in 1353, as a staging post on the road to Vientiane City. The French colonials changed the name to Vang Vieng in the 1890s.
The town expanded during the second Indochina War from 1964-1973, when the US built an air force base known as "Lima Site 6". The airstrip stands to this day, but is mostly used as a market. Years later, Vang Vieng welcomed backpackers on their way to Luang Prabang, and the town is now a major tourism destination surrounded by limestone outcrops.
During the war, the Royalists began building the Nam Ngum Dam between Vientiane Capital and Vang Vieng to bring electricity to Vientiane. The dam was completed in 1971, and later ceded to the Pathet Lao revolutionaries. The new government began logging the floor of the reservoir, and used some of the “mountaintop islands” as “re-education camps”.
Source: Lao Ministry of Information, Culture, and Tourism