You are or will be standing on Sir Joseph Bazalgette's masterpiece; without it London would stink to high heaven, the tube would not go round in circles and the Thames could freeze over -it's The Victoria Embankment.
Built on the shore of the River Thames making it narrower which prevents the Thames freezing in winter as the river now flows more rapidly. Underneath your feet is a massive sewer tunnel and the Circle and District lines, thankfully the trains goes through a separate tunnel.
You're looking for a cache smaller than a film canister attached by velcro. It's wheelchair user friendly.
Don't forget to note the codes if you're doing the Little Quest series.
Little Quest Geocaching (UK) Little Quest Statistics PLEASE NOTE THAT THE ORIGINAL CACHE IS TRAPPED BEHIND THE TEMPORAY FENCING. A TEMPORARY REPLACEMENT IS SLIGHTLY UP STREAM WHILST WORKS TAKE PLACE.