The Mayor's Thames Festival Night Carnival is a delight of luminous and candescent colour, which takes place in the failing hours of late September. It is a family affair, with the crowds lining the street watching, rather than dancing and getting hyper. It's perfect if you are a pleasant time seeking risk averse tourist.
The Night Carnival is part of a larger festival celebrating the river with open air arts, pyrotechnics, illuminations, river events and street theatre to name but a few.
In 2008 it will be taking place on the 13th and 14th September. See the route map here http://www.thamesfestival.org/site_assets/downloads/pdf/festival2007_map.pdf
