One of the most stunning remnants left from the First World War is the crater created when the British exploded 60,000lb of explosive called ammanol under the German lines.
Two tunnels were dug by professional miners and two chambers were made to contain the explosives.
At 7.30am on July 1, 1916, all 6.8 tons was detonated leaving two massive craters. One, Y Sap has since been filled in, but the other at La Boiselle created a hole in the ground which still remains. It is 300ft across and 70ft deep.
It would have been considerably larger at the time of the explosion, which was said to be heard in London.
Richard Dunning, from Woking, bought the land surrounding the crater in 1978 to save it for posterity. Since I took the photograph a few years ago visitors are no longer allowed inside the crater. A wooden walkway has also been built around the lip as foot-fall erosion was causing the edge to cave-in.
It is still a marvellous place to visit though.