The London Eye may be one of the city's most popular attractions, but there are many facts travelers don't know:
1. At 443 feet high, the London Eye is currently the fourth-largest Ferris wheel in the world, but it doesn't even crack the top 20 tallest structures in London itself. (For the record, the tallest building in the city is the Shard, topping out at 1,004 feet high.) Fun fact: The circumference of the wheel is 1,392 feet, so if it weren't a wheel, it would actually be taller than the Shard.
2. A ride on the London Eye takes 30 minutes, and it travels at a speed of about 0.6 miles per hour.
3. Husband-and-wife team David Marks and Julia Barfield came up with the idea for the Eye in response to a 1993 competition asking Londoners to design a new landmark celebrating the millennium. The contest was a bust, but Marks and Barfield's idea caught on, and the wheel opened on March 9, 2000. (It was behind schedule, so technically didn't open on the millennium, but that's okay.)
4. With more than 3.5 million people checking out the Eye every year, it's now the most popular paid tourist attraction in the U.K. The most popular free attraction is the British Museum, which sees more than 6 million visitors each year.
5. The operators of the Eye keep track of the celebs who've taken the most rides on the attraction: In the U.K., Kate Moss is the winner, with 25 spins. The American celebrity who holds that distinction is Jessica Alba, who's gone on the Eye a whopping 31 times.
6. The Eye has 32 capsules (one for each of the city's 32 boroughs), but they're numbered from one to 33. Why? As with many buildings and other structures, there is no No. 13 capsule—whether the superstition about that number is warranted or not, the cars skip from 12 to 14.
7. The entire wheel weighs more than 1,000 tons, or well over 1 million pounds. It was assembled flat and moved onto eight temporary islands on the River Thames; the structure was raised into place in September 1999. But the process wasn't without its snafus: one of the cables in the structure snapped before it was lifted, and had to be replaced.
8. One thing that differentiates the Eye from other Ferris wheels around the world is the fact that it's cantilevered, or supported on only one side. Wheels with similar structures include Orlando's new Orlando Eye, which opened this summer.
9. More than 5,000 people have gotten engaged on the Eye since it opened, with both sedate proposals and orchestrated flash mobs among the celebrations. (If you want to do the same in a private capsule, it'll cost you £360—about $559—but champagne is included.) More than 500 weddings have also happened there, with the first one taking place in 2001.
10. At one point during the London Restaurant Festival, the Eye turned into a pop-up dining spot: Celebrity chefs like Gordon Ramsay and Daniel Boulud served meals in one of the capsules for ten patrons, each of whom paid a pretty penny—in some cases, upwards of $30,000—for the pleasure.
11. There have been a few instances of people scaling the Eye, whether for entertainment or for political purposes. Magician David Blaine took a full rotation standing atop one of the wheel's pods in 2003; in 2004, a man dressed as Spider-Man climbed the attraction and spent 18 hours on top of a pod, allegedly to call attention to fathers' rights in the U.K.
12. In 2013, the Red Bull Academy turned the Eye into a rotating nightclub—well, technically, it turned 30 of the capsules into different parties to celebrate the U.K.'s club culture, with artists like Lily Allen, Mark Ronson, and Richie Hawtin performing in the pods.
13. As of this writing, selfie sticks are still allowed at the London Eye—although they're banned from many other London attractions, including the National Gallery of Art and the Wembley Arena.
14. Since the Eye opened in 2000, many cities—including Las Vegas, Seattle, and Atlanta—have opened observation wheels whose designs were directly inspired by the attraction. An exact replica of the wheel can be found about 30 miles outside of London—in miniature form, anyway. Legoland Windsor has a scale model of the Eye as part of its Miniland exhibit, which also features models of the Palace of Westminster, the Millennium Bridge, and Buckingham Palace.
15. On a clear day from the top of the London Eye, you can (almost) see forever—or, at least, as far as Windsor Castle.
