Grandpa Rainbow felt the neighborhood needed some color, so he picked up a paintbrush and went to work.

An architectural oddity hides in plain sight on this iconic London bridge.

Once part of an ancient international harbor, it's now an all-you-can-eat shrimp buffet for flamingos and other water birds.

The topiary maze at the Habsburg hunting lodge.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

A neo-Gothic church built to thank God for saving the Emperor of Austria from an assassination.

This former insane asylum now holds a pathological anatomy museum.

A patriotic medieval knight in driven-nail armor raised money for widows and orphans of WWI.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

On a winding Vienna side street, one museum has turned their windows into a monument to history’s peace-minded heroes.

A silly medieval mural preserved on the side of a Viennese house.

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

The ruins of a fairytale castle with a tumultuous history stand high atop the mountains.

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

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

A neo-Gothic mansion now houses a wunderkammer of analog tech that hits on all the senses.

Op-art architecture designed for happiness.

This Austrian museum celebrates the work of famous forgers and their inimitable imitations.

Macabre museum devoted to historical Viennese murders.

Baroque celebration of the end of the Great Plague of Vienna.

Legends surround an ancient tree trunk riddled with nails for good luck.

The world's largest concentrated solar power plant.

This Polish cave has housed a dragon, a brothel, and an enduring legend.