This is one of the very few intact windmills built by the Knights of St. John in the island nation of Malta.

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

These temples are among the oldest free-standing stone buildings in the world.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

A battle between nature and architecture in the Cambodian jungle.

This statue once earned the distinction as one of the "Three Major Disappointments of the World."

The busy transport hub is home to the tallest airport slide in the world.

This house is one of the most colorful in the country, and is the last remaining example of a historic villa.

5,000 skulls in memorial to those killed by the Khmer Rouge.

One of the largest caverns in the world has a maw large enough to stack cathedrals in.

Two thousand feline artifacts fill Malaysia's "Cat City."

The oldest museum in Borneo is a cornucopia of rare taxidermy and human skulls.

A bustling bazaar with an elaborate facade in Central Asia’s underrated capital.

The remains of an ancient city-state along the Silk Road.

This medieval citadel once guarded the western entrance of the Pamir Highway.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

An exquisite Baroque church in Vienna's old town.

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

A sculpture of the beloved author surrounded by characters from his fairy tales.

The inverted pyramid design of this station stands out amid Bratislava's urban landscape.

The largest fountain in Bratislava.

This spaceship sculpture in the middle of the Slovakian capital looks like it just crash-landed.