To cross a stream, road or valley (where the hold off caused by a flight of locks at possibly aspect could well be unacceptable) the valley is usually spanned by a navigable aqueduct – a famed example in Wales would be the Pontcysyllte Aqueduct (now a UNESCO Entire world https://donovanmpmjd.educationalimpactblog.com/58567916/rumored-buzz-on-canal-infantil