Valletta’s outdoor theatre stands within the ruins of a 19th-century opera house.

Natural arch offers panoramic views of Yangshuo's karst hills.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

This statue honors the thousands of Allied avians that served and died for France during World War I.

Tables of secondhand books fill the inner courtyard of this 17th-century stock exchange.

A giant bug impaled on a 75-foot-tall needle.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

Where George Lemaître discovered the expanding nature of the universe.

This unassuming stone bollard is a centuries-old marker denoting the center of the city.

Banished from town, this local jester concocted a clever return.

An installation that makes understanding the size of the universe a walk in the park.

The compass on its front was a handy tool for 17th-century merchants who needed to know the direction of the wind.

After 400 years of being closed to the public, this monastery's underground tunnels and secret garden are now a museum.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

A World War II-era sign in Valletta is a reminder of when Malta was besieged so severely that food needed to be rationed.

A glacial valley filled with silver beech trees in the mountains of Portugal.

This tower once served as a radar station during the Cold War.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

A piece of stonework relief commemorates the site where the Devil's rage, and odd apparel, destroyed a house.

Explore 400,000 years of humans' "battle against darkness" in this offbeat but thorough lamp museum.

Potato-peeling mannequins, Inca art, and a dangling tuber mobile help trace the history of fries at this Belgian museum.

Inside this former medieval prison is a collection of objects designed to inflict unbelievable pain and suffering on the human body and mind.

You can spot this teeny tiny stained-glass window from the Bonifacius bridge.