Waterlink Way is a pleasant cycle route nearby, runs from Thames mostly through open space and also mainly alongside some rivers (Ravensbourne and Pool) through to Cator park in Beckenham and beyond. Could continue along National Cycle Route 21 to Eastbourne if wanted!! Or more realistically, National Route 4 runs west along the Thames towards central London while National Route 1 also passes through Greenwich and heads east towards Dartford, along river. So you could start from ED, north to river then head east of west along Thames. http://www.sustrans.org.uk/ncn/map/route/waterlink-way