Exploration of Ex-military Tunnels, Fortifications and Underground Works in the Folkestone, Dover, and St. Margaret's Area of Kent.
This area of England, called Hellfire Corner in WW2, is the closest to the Continent and therefore was also thought to be the first part that would be invaded by an enemy. Consequently over the years, in times of tension or war, there have been programmes of fortification and defence which have left this area with an interesting legacy of tunnels, ditches, bunkers, shelters and fortresses cut into the chalk.
Plenty of interesing stuff with some good photos. I particularly enjoyed the page about sound mirrors which were new to me.