To cross a stream, highway or valley (wherever the hold off attributable to a flight of locks at either facet could well be unacceptable) the valley is often spanned by a navigable aqueduct – a popular instance in Wales will be the Pontcysyllte Aqueduct (now a UNESCO Globe Heritage https://canalinfantil33210.blogadvize.com/45058711/little-known-facts-about-musica-infantil