Bah, pity the Belgium farmer who's on top of this,
http://www.chavasse.u-net.com/messines.html
During the Battle of Messines ridge in 1917, 19 mines were exploded under the German frontline.
The resulting explosion was heard in London.
The least explosive used in one of the mines was 14,900 lbs, the most 95,600 lbs. The explosive used was Ammonal.
They averaged around a 200 foot crater, and i've stood in one, the Spanbroekmolen crater, and its big.
Alas 2 didn't go off. the war progressed and they were forgotten.
However, in a thunder storm in 1955 one of the remaining 2 decided to go bang, killing a cow that was unfortunate enough to be minding its own business in the area, the other is still out there waiting with the Ammonal deteriorating.......
Apparently its location has been pinpointed now,
http://www.1976design.com/blog/archi...exploded-bomb/
Don't know about you, but I'd have a serious aversion to thunder storms living there......