T he London Eye is the world's tallest observation wheel giving passengers views right across the capital city. Located on the South Bank of the Thames, it stands at 135 metres high and takes 30 minutes for one revolution. The viewing distance, on a clear day, is 25 miles.

It was designed by architects David Marks and Julia Barfield who, before starting their own company, worked for innovative architects, Sir Richard Rogers and Lord Norman Foster.

In 1995 the Sunday Times newspaper ran a competition in partnership with the Architecture Foundation for a Millennium Landmark for London. In response, Marks and Barfield had the idea of an observation wheel and set to work to develop the idea and address the practicalities. Another newspaper, the Evening Standard , took up and publicised their idea and British Airways offered sponsorship.

The London Eye , sometimes called the Millennium Wheel , is the largest observation wheel in the world (though often erroneously called a Ferris wheel ), and has been since its opening at the end of 1999 . It stands 135 metres (443 feet ) high on the western end of Jubilee Gardens , on the South Bank of the River Thames in Lambeth , London , England , north of Westminster Bridge . It is adjacent to London's County Hall , and stands opposite the offices of the Ministry of Defence situated in Westminster which it overlooks to the west.