To cross a stream, road or valley (the place the hold off because of a flight of locks at either aspect might be unacceptable) the valley may be spanned by a navigable aqueduct – a famed case in point in Wales could be the Pontcysyllte Aqueduct (now a UNESCO https://canal-infantil00998.ezblogz.com/68680277/fascination-about-musica-infantil