Here is a page about an art (craft?) project happening at Carpenters Road Lock on the Bow Back Rivers in London: the lock has changed quite a bit since I took the photo (above) in 2003.
What I thought was most interesting was the set of events organised at the lock. Canals of Dublin organises canal walks in, er, Dublin, but what about Waterways Ireland having lockkeepers doing talks and demonstrations?
Here are some links to sites with more information about the Bow Back Rivers in London:
An extensive Wikipedia article with schematic diagram
A political view from Mick Hartley
London’s Lost Rivers on pre-Olympic scenery (black background makes the text hard to read but the photos are good)