One by the Canal Grand Union 2026

One by the Canal Grand Union is a point-to-point half marathon along the Grand Union Canal, running from Uxbridge to Watford. It is held twice a year, in April and November, offering runners a towpath alternative to London road races, with clean air and long stretches beside the historic waterway. The route starts at Cowley Recreation Ground in Uxbridge and follows the canal north toward Cassiobury Park in Watford. Runners pass houseboats, pubs, country manors, and nature reserves, often while still only a short train ride from central London. The field is capped, and runners set off in waves so the narrower towpath sections do not get crowded. A pre-booked coach can take runners from the finish area to the start before the race, but there is no transport provided after the finish.