Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Island of Gorée' has mentioned 'World Heritage' in the following places:
Occurrence Sentence Text Source
[1][2] It is a UNESCO World Heritage Site and was one of the first 12 locations in the world to be designated as such in 1978.
Senegal's premier tourist site, the island was listed as a UNESCO World Heritage Site in 1978.
The island is a UNESCO World Heritage Site, since September 1978.