Look closely and you’ll notice that the color changes a third of the way up the tower.

The "lovely red Vega" of the legendary record-settling pilot.

Vienna's diversity-themed traffic lights were inspired by the Eurovision Song Contest.

Apartment complexes built into huge repurposed natural gas tanks.

Vienna's giant wonder wheel had a starring role in one of the greatest noir movies of all time.

Op-art architecture designed for happiness.

A spherical "micro-nation" in the heart of Vienna.

The oldest landmark of Toronto is a testament to shifting sands.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

A 20-meter (65-foot) robot towers over Tokyo Bay.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

A museum in the childhood house of a medical pioneer.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

An early 20th-century bullring converted into a modern shopping center.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The medieval woodcut-style artwork chronicles life in medieval London.

Sculptor Antony Gormley used chaos theory and fractal growth to design his tallest creation.

A quiet, semi-secret square with statues of Mahatma Gandhi, Virginia Woolf, and a conscientious objectors stone.

Children's hospital in London that operates on royalties received from Peter Pan, which J.M. Barrie signed over in 1929.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

The broken skateboards that became a poignant memorial to a murdered skater.

Museum dedicated to the UK's first charity for abandoned children, with keepsakes of the mothers who left them behind.