To cross a stream, highway or valley (wherever the delay brought on by a flight of locks at either facet can be unacceptable) the valley might be spanned by a navigable aqueduct – a renowned example in Wales is the Pontcysyllte Aqueduct (now a UNESCO Environment Heritage Web-site) over https://musicainfantil85048.jiliblog.com/93568284/considerations-to-know-about-urso-fofo