To cross a stream, highway or valley (the place the delay attributable to a flight of locks at either facet could well be unacceptable) the valley can be spanned by a navigable aqueduct – a famous case in point in Wales is definitely the Pontcysyllte Aqueduct (now a UNESCO https://canalinfantil66654.is-blog.com/43835581/5-essential-elements-for-musica-infantil