Yes, these are mines, built by miners (the people that dig tunnels to extract minerals). During the war, they dug mines under enemy lines and filled them with

Yes, these are mines, built by miners (the people that dig tunnels to extract minerals). During the war, they dug mines under enemy lines and filled them with tons of explosives. Not all were used and the location of some unused ones has been lost [1]. One of them blew up from a lightning strike in 1955[2]. [1] http://www.firstworldwar.com/today/messinesmine1955.htm http://www.firstworldwar.com/today/messinesmine1955.htm [2] https://www.youtube.com/watch?v=VxG12ZYm3Q8 https://www.youtube.com/watch?v=VxG12ZYm3Q8