Blisworth

This strange tower is actually an airvent, ventilating the Blisworth canal tunnel.

We were walking along the towpath of the Grand Union Canal, but had to walk above the Blisworth Tunnel, which is 1.75 miles long.

It was a sponsored walk for the British Heart Foundation. Distance: 17 miles from Wolverton to Franklin's Gardens, where Northampton Saints were playing their last game of the season against Worcester.