Mark Chatterton, author of the book Britain's Road Tunnels, tells us why the 50 or so road tunnels found in and around London deserve more than just a passing glance.
As a young boy, I first travelled under the Mersey Tunnel from Liverpool to Birkenhead and was hooked.
There is something quite magical for a child (and for many adults) to leave one place behind, head underground and surface into a completely different world. In London, there are so many road tunnels that you can pass through on your journey across the capital.
We can easily take them for granted, yet these engineering marvels often reveal unexpected information.
Some are well known such as the Blackwall and Limehouse Link tunnels. Others are hidden away from the main roads, such as the one in Abbot Road in Poplar, which takes you under the Blackwall Tunnel approach road.
Driving in London? Chances are you'll pass through a road tunnel...
Say you were going from the end of the M11 in north east London south, via the A12 to the A2 at Eltham in south east London; you would pass through no less than six tunnels.
Due to the redevelopment of London's Docklands there is a large cluster of road tunnels east of Tower Bridge. You'll find some in central London too though, such as the ones at Upper Thames Street and at Hyde Park Corner — and further west at Hangar Lane.
Coming north over Waterloo Bridge, you can head into an unusually narrow, one-way tunnel known as the Strand Underpass; until the 1950s it was used solely by trams making their way to and from Kingsway.
Near Canary Wharf, at Westferry Circus is another unusual tunnel — if it can be called a tunnel at all. Motorists are given a choice here; take the conventional roundabout above ground, or go underground, also on a roundabout, but in a tunnel, which has four separate entrances/exits.
You don't need a car to use London's road tunnels...
Many are accessible to both pedestrians and cyclists. Beech Street tunnel at the Barbican has pavements on both sides. (We'll gloss over the fact that Londonist once branded it one of central London's most wretched streets.)
And believe it or not, you are still able to walk or cycle through one of London's oldest road tunnels: the Rotherhithe Tunnel. Personally, I wouldn't recommend it, what with the constant flow of traffic going past at just 20mph — and more than enough exhaust fumes to affect your lungs.
More palatable for pedestrians are the tunnels under the railway tracks leading to some of London's railway terminals, particularly those around Waterloo and London Bridge. Here you might find an entrance to a club, café or a taxi firm lurking in the depths.
Many road tunnels have formed the backdrop for music videos, TV shows and album covers...
Both Coldplay's Fix You and the Specials' Ghost Town videos feature tunnels near London Bridge station. Beech Street tunnel has also proved a popular choice for artists; you'll see it in Kylie Minogue's Giving You Up, and Too Much to Ask by Niall Horan.
The Rotherhithe Tunnel features in the 1951 film Pool of London as the setting for a police chase, as well as in the opening credits for the 1970s/80s TV crime series The Professionals.
London's oldest road tunnel, the Blackwall Tunnel, was one of several locations that made an appearance in 2002's 28 Days Later. And former Wishbone Ash frontman, Martin Turner used one of the London Bridge tunnels on the album cover for his solo album, Walking The Reeperbahn.
Nearby on the Embankment, running next to the Upper Thames Street tunnel on the north side is the Castle Baynard Street tunnel. Its entrance is hidden to the left of the Upper Street tunnel to which it runs parallel, but only in a west to east direction. This tunnel, too, has a claim to fame: it starred in the James Bond film Spectre.
These tunnels aren't just woven into the road network — but the very fabric of our culture.
Britain's Road Tunnels by Mark Chatterton, published by Amberley Publishing, available now, RRP £14.99