Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Pyu Ancient Cities' has mentioned 'City walls' in the following places:
Occurrence Sentence Text Source
In that article, the author adds upon his research in other's article, they also recorded old photo of founded place which is already surveyed in nine major burial terraces outside the southern city walls, old Buddhist monuments including the complex at "Beikthano" city and the queen "Panhtwar" cemetery.
Stupas and monastic buildings have also been excavated within the city walls.
The urban footprint of each city, demarcated by the well-preserved moated city walls, remains highly legible two millennia after their initial construction.