This demanding run along the Thames is one of the most popular events in the British ultra running calendar. Previously known as the Thames Trot, the event takes in 47-miles from Iffley in Oxfordshire to Henley-on-Thames. Runners will enjoy the company of England’s largest river as it makes its way past ever-changing scenery, beautiful houses and traditional rowing clubs. Expect everything from tarmac paths to muddy trails on this interesting and challenging course.