A packhorse bridge is a bridge intended for packhorses (horses loaded with side bags or panniers) across a river or stream. Typically a packhorse bridge is narrow (just one horse wide) and has low parapets so as not to obstruct the horses panniers. This one, the Allerford Packhorse Bridge was used by wool-laden mules, donkeys or horses to cross the river Aller, is thought to be medieval in origin. It is classified as an Ancient Monument and is on the 'Heritage at Risk' register.... via http://500px.com/photo/86954167
