Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Serengeti National Park' has mentioned 'World Heritage' in the following places:
Occurrence Sentence Text Source
Because of its biodiversity and ecological significance, the park has been listed by the United Nations Educational, Scientific and Cultural Organization as a World Heritage Site.
The property is contiguous with Ngorongoro Conservation Unit, an area of 528,000ha declared a World Heritage Site in 1979.