When the London Eye opened in 2000 it was intended to be a temporary attraction – but it proved so popular that it became a permanent fixture of the skyline, making towering observation wheels the new must-have landmark of the new millennium.

Since then, more than 18 giant observation wheels have been built around the world – but despite the title of “world’s tallest” changing hands three times, the actual height of the tallest observation wheel has only risen from 135-metres in 2000, to 169-metres in 2014 when Las Vegas completed the High Roller.