Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Castles and Town Walls of King Edward in Gwynedd' has mentioned 'Trade' in the following places:
Occurrence Sentence Text Source
All the defensive attributes are within the boundary but as the towns were an integral part of their defensive, administrative and economic arrangements, and their waterside position contributed to their defence and trade, the full range of attributes could be seen to extend beyond the narrow boundaries.