Assertion: tower's site | /r/AtLocation | use
Facets:
value: for a prolonged period
type: TEMPORAL
Source sentences:
text: A bank and ditch enclosure was a simple form of defence, and when found without an associated motte is called a ringwork; when the site was in use for a prolonged period, it was sometimes replaced by a more complex structure or enhanced by the addition of a stone curtain wall.