Mesa Verde National Park (UNESCO/NHK)

A great concentration of ancestral Pueblo Indian dwellings, built from the 6th to the 12th century AD, can be found on the Mesa Verde plateau in south-west Colorado, USA at an altitude of more than 2,600 m. Some 4,400 sites have been recorded, including villages built on the Mesa top. There are also imposing cliff dwellings, built of stone and comprising more than 100 rooms. Source: UNESCO TV / © NHK Nippon Hoso Kyokai URL: http://whc.unesco.org/en/list/27/