Video: Soar over the city with the London Eye -- in 4D!

As if soaring 135m above the capital aboard the Merlin Entertainments London Eye* isn't enough, visitors will now have the chance to see the first ever 3D aerial film of our fair city.

The Eye, already the UK's most popular paid-for tourist destination, has launched a new £5m immersive attraction involving a 3D film showing the Big Smoke from the sky, which you can experience in -- get this -- 4D. As every clever Tom, Dick and Harry has pointed out, travelling in the fourth dimension is usually taken for granted, but in this case the fourth dimension isn't time.

Instead, the 3D film screening is augmented by nine different effects, such as the whoosh of the wind as the film sweeps through clouds, the splash of rain and snow as we swoop over London, and even the smell of fireworks on New Year's Eve. The three-and-a-half minute film is free to all visitors, with the queue to board the 135m-high Eye snaking through the custom-built auditorium -- or should we say, '4Dtorium'. You can have that, Merlin, free of charge.

It's a clever way of breaking up the queuing time, and you get the bonus of passing screens showing the development of the Eye. It's a fascinating watch, as we see the wheel and capsules being designed, built, transported to London, and hoisted into place for its launch in 1999.

We popped down to the South Bank to take a look, chatting with director Julian Napier and 3D producer Phil Streather about the technology used and the challenges involved, and getting an exclusive sneak peek behind the scenes. Hit play to see more.

*In case you were wondering, it stopped being the British Airways London Eye in 2008 after Merlin, the second largest theme-park operator in the world (after Disney), bought the wheel's owners, the Tussauds Group. Each ride is still referred to as a flight, though.