A vast Communist-era exhibition space in the Bulgarian capital.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.

A striking symbol of the Bulgarian capital.

A collection of art from Bulgaria's time as a communist state.

A Bulgarian monument to Russia's role in World War II is constantly being painted in pop culture protest.

A largely overlooked statue that may commemorate the first publication of 'Don Quixote' outside of Spain.

A bronze statue of the fictional character nicknamed "Mrs. Hat" from a beloved Belgian comedy.

A little sculpture with a large wardrobe.

Belgium’s famous peeing statue has worn many hats (and coats, and pants), which are on display at this small museum.

This enormous steel tube is the biggest speaking horn in the world.

A wonderfully kitsch bookstore the size of a supermarket.

The former home and studio of Belgian artist Antoine Wiertz is now a museum dedicated to his work.

One of Hollywood's most iconic actresses was born in an upscale Brussels neighborhood in 1929.

The world's tallest circular building is loaded with symbolism, but many just see a big donut.

The world’s tallest outdoor lift stretches along the stone pillars that inspired the floating mountains in the movie “Avatar.”

The latest in a series of long glass bridges suspended at terrifying heights.

For those with no fear of heights: a skywalk 4,700 feet up on a Chinese mountain.

A total of 999 stairs lead visitors through a massive hole in a mountain known as the Gateway to Heaven.

This vertical pinnacle in China was the inspiration for the floating mountains in the movie “Avatar.”

Not one, not two, but three natural bridges remain in this captivating spot post-sinkhole.

Look up as you explore Baku’s old town to find a monument to the local feline population.

A massive collection of petroglyphs dating back some 40,000 years.

This mysterious but iconic tapered tower appears in many Azeri fairytales and legends.

The building's fluid, wavelike walls are a true feat of architectural ingenuity.