Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Old City of Berne' has mentioned 'City walls' in the following places:
Occurrence Sentence Text Source
The only major cross streets (going north and south) developed along the city walls, which were moved to allow the city to expand.
However, as the city grew, people began settling outside the city walls.
By the early nineteenth century, Bern had expanded as far as it could within the old city walls.
An increasing number of people were living outside the city walls in neighbouring communities.