To cross a stream, street or valley (where the hold off brought on by a flight of locks at possibly facet can be unacceptable) the valley could be spanned by a navigable aqueduct – a popular illustration in Wales is definitely the Pontcysyllte Aqueduct (now a UNESCO Globe Heritage https://urso-fofo88888.dsiblogger.com/70111240/how-urso-fofo-can-save-you-time-stress-and-money