The London Underground, commonly known as The Tube, is a
rapid transit system serving Greater London, England. The oldest
underground railway in the world, its first section opened in 1863.
In 1890, it became the first to operate electric trains. 
With the outbreak of World War II, many Underground stations
were used as air raid shelters. The Underground provided an escape
route to the countryside for over 200,000 children, and is said to
have sheltered another 177,500 people. Overcoming early objections
to overnight guests, the Underground eventually hosted 22,000
bunks, along with latrines and catering facilities. Some stations
were even set up with libraries and classrooms. Eight such
deep-level shelters were constructed under London stations.
More recently, on 18 November 1987, a massive fire swept through
the busiest station on the network, the King's Cross St Pancras
tube station, which served 200,000 passengers daily. Thirty-one
people perished. The fire started in a wooden pre-WWII escalator
shaft, quickly burning through to the Piccadilly Line above, and
upward to the top level entrances and ticket hall. Although smoking
had been banned in the subsurface sections of the Underground in
1985, a consequence of the 1984 Oxford Circus fire, the Kings Cross
fire was most probably caused by a discarded match that fell onto a
dirty, greasy running track below. The cleaning staff at the
station had recently been cut from 14 to 2. The tragedy led to the
elimination of all wooden escalators at all Underground stations
and pledges of greater investment.
About the cache---- You do NOT have to traverse a ravine to get
to this cache regardless of what your GPS tells you. Walk past the
ravine and there is a clear walkway to the cache with no climbing
involved. Please try to keep the cache covered so it doesn't become
iced in. Happy Hunting!