Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Site of Palmyra' has mentioned 'City walls' in the following places:
Occurrence Sentence Text Source
"[387] Palmyra's army protected the city and its economy, helping extend Palmyrene authority beyond the city walls and protecting the countryside's desert trade routes.
The large scale funerary monuments outside the city walls in the area known as the Valley of the Tombs display distinctive decoration and construction methods.