Assertion: bridge's tower | /r/CapableOf | sit on a bluff or canyon edge
Facets:
value: in some circumstances
type: TEMPORAL
Source sentences:
text: In some circumstances, the towers may sit on a bluff or canyon edge where the road may proceed directly to the main span, otherwise the bridge will usually have two smaller spans, running between either pair of pillars and the highway, which may be supported by suspender cables or their own trusswork.