We join the River at the Woolwich ferry pier and within a few minutes we've reached the Thames Barrier. The great silver domes could be made for a day like today, they blend perfectly with the dull skies and river. From here we head towards Canary Wharf, something which we appeared to be doing for the next 3 hours as it looms menacingly to our right The lazy meanders of the Thames mean we pretty much walk around three sides of Canary Wharf and by the time we leave it behind I'm glad to see the back of it!