To cross a stream, street or valley (exactly where the delay because of a flight of locks at possibly aspect can be unacceptable) the valley could be spanned by a navigable aqueduct – a well-known example in Wales is definitely the Pontcysyllte Aqueduct (now a UNESCO Entire world Heritage https://canalinfantil12211.thezenweb.com/facts-about-urso-fofo-revealed-75333370