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
Indigo Tunnel of the parallel Baltimore and Ohio railroad line on the opposite side of the Potomac River. The tunnel was acquired by the National Park Service in 1980 and became part of Chesapeake and Ohio Canal National Historical Park. The Park Service has identified bat colonies living in the tunnel and has closed the tunnel to the public in order to protect the colonies. Indigo Tunnel Indigo Tunnel is an abandoned railroad tunnel in Allegany County, Maryland, located about east of Little Orleans. Built by the Western Maryland Railway (WM) in 1904, Indigo was the company's longest tunnel. It was part