vat phou, laos

11th—13th 7th angkor asia back base bce brick building buildings built carving cells centred centuries century champasak complex consequent crocodile dating district early erected hindu khao khmer kilometres lao laos megalithic mekong mighty mount offering oldest one onsite period phonthong phou phu place places platforms pre-angkor pre-historic province ruined sacred sanctuary serpent site southeast southern spring sprit stairs stone structures surviving temple temple-mountain tutelary vat wat worship