Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Monasteries of Haghpat and Sanahin' has mentioned 'World Heritage List' in the following places:
Occurrence Sentence Text Source
Described as a "masterpiece of religious architecture and a major center of learning in the Middle Ages", Haghpat monastery, together with Sanahin Monastery, was placed on UNESCO's World Heritage List in 1996.
The constructions included in this property, as well as its landscape, have not been modified since inscription on the World Heritage List.