The Thames Ring 250 is an iconic 250 mile trail race starting in Streatley-on-Thames and following an anti-clockwise loop East along the Thames, up the Grand Union Canal and back to the Thames via the Oxford canal and finally back to the start.
The route almost entirely on canal and riverside paths and relatively flat, though not as easy as you may think.
Runners have 100 hours (4 days 4 hours) to complete the run, navigating using maps, gpx files and being supported by checkpoints every 25 miles or so.
It’s an extremely tough run testing runners endurance to the limit along with many long hours with little sleep and dark nights.
The first race of this distance in the UK and for many years the longest non-stop race in europe.