This was more of a camera/long exposure/torch experimentation than an explore but some of the pictures turned out half decent to I thought I would post up a quick report.
Old Warden Tunnel was built between 1853 and 1857 to connect Bedford to Hitchin, before joing the main line to London. It was closed in 1962 but not as a result of Dr. Richard Beeching’s ‘Beeching Bombshell’ report. The tunnel is straight and runs for 882 yards. The western end is half bricked up but with a large grille at the top to allow access for bats. I’m no bat expert but I have heard that a rare bat called the Barbastelle has been found in this tunnel from time to time. The eastern end has been partially backfilled and the trackbed at this end is flooded quite deeply. Internally there are some interesting Calcite formations on the walls and at the far end a small crystalline ‘Calcite Lake’ has formed.