Mỹ Sơn is a UNESCO World Heritage Site in South-Central Vietnam, and is believed to be the longest inhabited archaeological site in Indochina. Much of the site was destroyed by US carpet bombing during the Second Indochina War (US: Vietnam War; Vietnam: American War.) It is considered one of the foremost Hindu temple complexes in Southeast Asia, and one of the most important heritage sites of this nature in Vietnam. Mỹ Sơn was recognized as a World Heritage Site by UNESCO in 1999, under its criterion C(III) — evidence of an Asian civilization which is now extinct.