Plaque at the south portal of the Blisworth Tunnel

The Blisworth Tunnel was constructed between 1793-1805, it is the third-longest navigable canal tunnel on the UK canal network, at 3,075 yards (2,812 m) in length. At its deepest point it is about 143 feet (43m) below ground level. It has no tow path inside, but is wide enough for two barges to pass in opposite directions.