You may not realise it but your daily commute on the Underground might be taking you past London’s long disused “ghost” tube stations or the 23 mile-long “Mail Rail” that once carried four million letters a day.
If you travel the full length of the Northern Line the tube will take you past several deep-level WWII shelters that were each capable of housing up to 8,000 people. Once a hive of activity, they are now left in almost perpetual darkness while the Tube network continues around them.
Elsewhere, you will pass through some of the more grizzly remnants of medieval London. Between South Kensington and Knightsbridge, the Piccadilly Line curves to avoid one of the city’s many plague pits where Londoners were buried on mass as Yersinia pestis swept the city in the 14th and 17th centuries.
Some hints of this underground world can be seen at street level – the odd ventilation shaft or drain cover might lead to an abandoned military bunker or one of London’s 13 subterranean rivers.
At Sloane Square Station one of these waterways, the River Westbourne, flows through a large Victorian pipe that runs straight through the station above the trains.
It can be a tough world to get around but today there is a growing community of urban explorers who are detailing their own underground adventures in books and blogs and more of these sites are being opened to the public.