To cross a stream, highway or valley (wherever the hold off because of a flight of locks at possibly aspect will be unacceptable) the valley may be spanned by a navigable aqueduct – a well-known example in Wales is the Pontcysyllte Aqueduct (now a UNESCO Environment Heritage Web-site) over https://musica-infantil13277.total-blog.com/the-ultimate-guide-to-urso-fofo-62416125