Mind your head!

Stoke Bruerne in Northamptonshire is a great place to take a walk, there are two pubs, neither of which is up to much unfortunately. The Blisworth Tunnel is situated not very far from here, at 3,076 yards (2,813m) long it is the third-longest navigable canal tunnel on the UK canal network and the ninth-longest canal tunnel in the world. At its deepest point it is 143 feet (43m) below ground level.
The tunnel has no tow path inside, but is wide enough for two narrow boats to pass in opposite directions. Played around with this shot somewhat and liked this effect more than any other.