The London Eye, also known as the Millennium Wheel, is the tallest (135 metres (443 ft )) Ferris wheel in Europe, and has become the most popular paid tourist attraction in the UK, visited by over 3 million people a year.

At the time it was erected it was the tallest Ferris wheel in the world, until surpassed by the The Star of Nanchang (160m) in May 2006, and then the Singapore Flyer (165m) which opened on February 11, 2008.

The wheel carries 32 sealed and air-conditioned passenger capsules attached to its external circumference. Each capsule holds approximately 25 people, who are free to walk around inside the capsule, though seating is also provided. It rotates at 26 cm (10 in) per second (about 0.9 km/h (0.5mph) so that one revolution takes about 30 minutes.