Blisworth Tunnel has no tow path inside, but is wide enough for two narrowboats to pass in opposite directions. Work began in 1793, but errors by contractor left a wiggle in the tunnel, and after three years work it collapsed due to quicksand, claiming the lives of 14 men. It was then decided to begin again with a new tunnel. By the time the rest of the Grand Junction Canal had opened between London and Braunston, Northamptonshire in 1800, apart from the crossing of the River Great Ouse, the section of canal from Blisworth to the lower end of Stoke Bruerne locks
Grand Union Canal brings the canal to the bottom of the Stoke Bruerne flight of seven locks. At the top of this flight is the Stoke Bruerne Canal Museum followed shortly by Blisworth Tunnel, at one of the longest of UK canals. Once clear of the tunnel, the canal passes Blisworth village and reaches Gayton Junction where the Northampton Arm branches off to the east. This arm has 17 narrow locks as it descends to join the navigable River Nene (see below). The long level stretch continues past several villages including Nether Heyford and Weedon Bec and is very rural in character. At