To cross a stream, street or valley (wherever the delay attributable to a flight of locks at possibly facet might be unacceptable) the valley might be spanned by a navigable aqueduct – a renowned instance in Wales will be the Pontcysyllte Aqueduct (now a UNESCO World Heritage Web page) https://stephenfjmru.blogpostie.com/58358675/detailed-notes-on-musica-infantil