There's a world of basements beneath our feet. Here are seven of our favourites.
Bank of England
Beneath the Bank of England lie several thousand 28lb bars of 24-carat gold. Unfortunately the 4,600 tonnes of the stuff — worth £73bn — isn't all ours; the Bank holds a lot of it on behalf of foreign depositors in the concrete-lined vaults beneath Threadneedle Street. To get your grubby mitts on a real gold bar, visit the Bank of England Museum, where you can show off your strength by lifting one.
Visitors to the British Library see just a tiny portion of the works kept here. The majority of their 15 million books are stored underneath the library, over four levels (equivalent to eight storeys) of metal shelves. Kept in temperature-controlled conditions up to 75ft below ground, periodicals and audio files are also stored in this word-filled warren. Visits to this treasure trove (which only opened in 1997) are not on offer to the public, although certain publications are available to those researchers and scholars who possess the ultimate Golden Ticket — the legendary Reader's Pass. Better get swotting.
Selfridges bargain basement
When Harry Gordon Selfridge opened his famous department store in 1909, he was keen on offering quality goods to people on every income, inventing the concept of a 'bargain basement'. Sadly, today the only real 'bargains are at the store's bi-annual sales. However, venture beneath the shop floor and you'll find a 'sub' and a 'sub-sub' basement, part of which was inhabited by the US Army Corps during the second world war. Apparently Selfridge himself wanted to turn it into a tube station named, er, Selfridges.
London Silver Vaults
Unlike the Bank of England’s precious metals, the London Silver Vaults' are on view — and on sale — to the public. The vaults were established in 1876 as the Chancery Lane Safe Deposit. Along the corridors you'll pick out framed pictures of famous clients, notably the king of bling Liberace. About 30 competing independent businesses offer their wares here, in what is one of the world's largest silver markets. Whether you're after jewellery or goblets, chess sets or ostentatious receptacles for salt, anything and everything (provided it is made of silver) is available.
Below Guildhall are the East and West Crypts; the East being the oldest, dating back to the time of Edward the Confessor in 1042, and the West Crypt built a little later, in the 12th century. Originally used for banquets and royal occasions, the Crypts caved in during the Great Fire of London, and didn’t reopen until 1973. Today they are the largest medieval crypts in the city, and notable for their stained glass windows, which depict figures such as Chaucer, Sir Thomas More and Samuel Pepys. It's possible to see them for yourselves; they can be hired for events.
The Hackney Mole Man's basement
William Lyttle, known as the 'Mole Man' was Hackney’s resident burrower. What began as a venture to dig a wine cellar soon turned into tunnels over 60ft long, in which he kept suitably themed books such as At the Earth's Core: A Tarzan Adventure. Lyttle's underground antics soon began to hit electricity and water supplies, and holes appeared in pavements. After being evicted twice, Lyttle was placed in a high-rise block of flats, where digging was off the cards, and died there two years later.
If you're in need of a basement-based bevvy, make your way to this underground bar beneath Soho, which features cocktails with bizarre names like Not a Pornstar and Salty Granny.
Which London bunker would you most like to visit? Tell us in the comments below.