Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Ecosystem and Relict Cultural Landscape of Lopé-Okanda' has mentioned 'Valley' in the following places:
Occurrence Sentence Text Source
The National Park includes the River Ogoouxc3xa9 valley, one of the principle migration routes for the diffusion of people and languages, including the Bantu, to Central and Southern Africa, in the Neolithic and Iron Age, as evidenced in extraordinary number of substantial settlements sites and an extensive collection of rock art petroglyphs.
Criterion (iii): the rich archaeological ensembles of the middle stretches of the River Ogoouxc3xa9 Valley demonstrate 400,000 years of almost continuous history.
Criterion (iv): the collection of Neolithic and Iron Age sites together with the rock art remains appear to reflect a major migration route of Bantu and other peoples along the River Ogoouxc3xa9 valley to the north of the dense evergreen Congo forests from West Africa to central east and southern Africa, that has shaped the development of the whole of sub-Saharan Africa.
The integrity of the cultural sites lies mainly in their relationship to one another along the River Ogoouxc3xa9 Valley corridor which facilitated waves of migrations and subsidiary, later archaeological sites which fan out along the lesser river valleys within the forest.
It would be desirable if at some point in the future that part of the river valley between the north-west corner of the National Park and the historic ensemble to the north-west could be included so that the integrity of the river corridor as a whole could be protected.
Without a mission to the main archaeological sites in the River Ogoouxc3xa9 Valley, details of the state of conservation of the cultural property cannot be recorded.