4 Best Sights in London, England

To mark the start of the new millennium, architects David Marks and Julia Barfield devised this instant icon that allows Londoners and visitors alike to see the city from a completely new perspective. The giant Ferris wheel was the largest cantilevered observation wheel ever built at the time and remains one of the city's tallest structures. The 30-minute slow-motion ride inside one of the enclosed passenger capsules is so smooth you'd hardly know you were suspended over the Thames. On a clear day you can see up to 25 miles, with a bird's-eye view of London's most famous landmarks as you circle 360 degrees. If you're looking for a special place to celebrate, champagne can be arranged ahead of time.

Buy your ticket online to avoid the long lines and get a 15% discount. For an extra £10, you can save even more time with a Fast Track flight (check in 15 minutes before your "departure").

You can also buy a combination ticket for The Eye and other London attractions (check online for details) or combine with a river cruise for a 40-minute sightseeing voyage on the Thames. In December, there's a scenic ice rink just below the wheel.

It may not have become the essential commuter route its makers envisioned, but this cable car, which connects Greenwich Peninsula with the Docklands across the Thames, offers spectacular views from nearly 300 feet up. The journey takes about 10 minutes each way and cable cars arrive every 30 seconds.

At 800 feet, this addition to the London skyline currently offers the highest vantage point in western Europe. Designed by the noted architect Renzo Piano, it has attracted both admiration and disdain. Although the building itself is generally highly regarded, many felt it would have been better sited in Canary Wharf (or perhaps Dubai), as it spoils views of St. Paul's Cathedral from traditional vantage points such as Hampstead's Parliament Hill. No matter how you feel about the building, there's no denying that it offers a spectacular 360-degree vista over London (extending 40 miles on a clear day) from viewing platforms on Level 69 and the open-air skydeck on Level 72—almost twice as high as any other viewpoint in the city. Digital telescopes provide information about 200 points of interest.

A weather guarantee lets you return on a more clement day if visibility is seriously impeded, and various themed events like silent discos or early-morning yoga classes are offered at an extra charge. Admission is by timed ticket only. If you find the price as eye-wateringly high as the viewing platforms, a less dramatic but still very impressive (and free) view is from the lobby of the Shangri-La hotel on the 35th floor, or, in the evenings, the hotel's chic Gong bar on the 52nd floor (over-18s only).

Certainly one of the most original ways to see London, this thrilling urban expedition takes you on a 90-minute journey across the giant dome of The O2 arena. After a short briefing, you're dressed in safety gear and taken in small groups across a steep walkway, running all the way to the summit and down the other side. The high point (literally) is a viewing platform, 171 feet aboveground, with magnificent views of the city. On a clear day you can see for 15 miles (that's as far as Waltham Abbey to the north and Sevenoaks to the south). Climbs at sunset and twilight are also available, but the best trips are on nights when London is lit up by fireworks, such as New Year's Eve, Fireworks Night, and Diwali.

It's quite an experience, but unsurprisingly there are restrictions: you have to be at least eight years old, taller than 4 feet, have a waist measurement that's less than 49 inches, weigh less than 286 pounds, and pregnant women can't make the climb at all. Wheelchairs can be accommodated on a few tours. Advance booking is essential.