The London Eye, or the Millennium Wheel, is a cantilevered observation wheel on the South Bank of the River Thames in London. It is Europe's tallest cantilevered observation wheel, and the most popular paid tourist attraction in the United Kingdom with over three million visitors annually. It has made many appearances in popular culture. The structure is 135 metres tall and the wheel has a diameter of 120 metres. When it opened to the public in 2000 it was the world's tallest Ferris wheel.