A geological oddity topped with a 2,000-year-old pagan temple.

Armenia's premier center of astrophysical research was established during the Soviet era.

This ancient monastery complex was transformed from an island to a peninsula when the lake was partially drained.

Natural rock formation, or biblical artifact that saved Earth's wildlife two by two?

Standing proud atop a Turkish bluff, this Ottoman palace has retained its grandeur despite being abandoned for centuries.

This 135-year-old weather station studied the effects of the climate on human health.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

An eclectic art form practiced by untrained masters is celebrated at this museum in the heart of Zagreb's old Upper Town.

Historic medieval fortified city in southwest France.

This ancient theater was once the home of fierce gladiatorial battles.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

For those late-night mollusk cravings.

The experimental test tracks of a retro-futuristic monorail still stand in the French countryside.

This whimsical castle of grottoes was the labor of love of a French postman, and one of the greatest achievements of outsider architecture.

Lyon's miniature version of the Eiffel Tower was built as a statement in support of French secularism.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

The great Italian Renaissance painter was laid to rest here in the Chapel of Saint-Hubert.

The world's tallest bridge is also possibly the most elegant.

The world's largest reflecting pool is just two centimeters deep.

A Gothic cathedral created from volcanic rocks.

France's high-tech, future-themed amusement park.

The vibrant buildings in the “capital of the comic strip” celebrate the art form that made it famous.

Ancient paintings known as the "Sistine Chapel of Cave Art."