To cross a stream, street or valley (exactly where the hold off attributable to a flight of locks at either side could well be unacceptable) the valley is often spanned by a navigable aqueduct – a popular instance in Wales would be the Pontcysyllte Aqueduct (now a UNESCO Planet https://donovanadays.fitnell.com/77929341/the-single-best-strategy-to-use-for-musica-infantil