To cross a stream, street or valley (the place the delay attributable to a flight of locks at possibly aspect might be unacceptable) the valley is often spanned by a navigable aqueduct – a well known illustration in Wales may be the Pontcysyllte Aqueduct (now a UNESCO Planet Heritage https://troybauja.yomoblog.com/43960906/how-urso-fofo-can-save-you-time-stress-and-money