The London Eye, built for the year 2000 millenium, soon became an important landmark on the Thames, and is now a must-see for many visitors.
What's the appeal? Well, there's the the striking visual appearance of this giant spoked circle on the banks of the Thames; plus the chance to get a birds-eye view of London. If the weather's clear, visitors can get a 25-mile view.
The London Eye stands 135 meters high, and is the sixth tallest structure in London. It's "flight" is a gentle and slow half-hour in capsules holding 25 passengers.
Interesting factoid: sections of the giant wheel rim of the London Eye were floated in on the Thames, and assembled on the spot.