To cross a stream, road or valley (exactly where the delay caused by a flight of locks at possibly facet could well be unacceptable) the valley is often spanned by a navigable aqueduct – a popular instance in Wales may be the Pontcysyllte Aqueduct (now a UNESCO Globe Heritage https://canal-infantil00998.ezblogz.com/68680277/fascination-about-musica-infantil