To cross a stream, highway or valley (in which the hold off caused by a flight of locks at both facet can be unacceptable) the valley is usually spanned by a navigable aqueduct – a famous instance in Wales is definitely the Pontcysyllte Aqueduct (now a UNESCO Entire world https://canalinfantil34321.ltfblog.com/35892857/5-easy-facts-about-musica-infantil-described