London Millennium Bridge with St. Paul's Cathedral in the background, London, England

The Millennium Bridge at 20

The view you're seeing was first made possible exactly 20 years ago, but a photo from the same spot on June 10, 2000, might've come out a tad blurry. That's because when the London Millennium Bridge opened to flocks of pedestrians on that date, it wobbled so much it was closed after just two days. But the bridge reopened with improvements in 2002, and today it's stable in terms of not only lateral g-force but also photo-op popularity.

Famous for its hodgepodge of bleeding-edge design and preserved historic architecture, the London cityscape is full of anachronistic scenes like this. The bridge and St. Paul's Cathedral, seen a few blocks north across the Thames, were built about 300 years apart (just a fraction of London's nearly 2,000-year history). If we could about-face, the contrast of eras would be even more pronounced: Behind us near the bridge's south end lies a reconstruction of Shakespeare's Globe Theatre neighbouring the Tate Modern, an art museum converted from a mid-20th-century power plant.