An emerald-green grotto just a short trip from Austin.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

On Japan's Tashirojima Island, cats are king.

A magical place that lets you play in and explore the world of Studio Ghibli.

The macabre collection of Jacques Sirgent, an expert scholar on the undead and all of their trappings.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

One of the largest ancient geoglyphs in the world is a tall desert god used for predicting the weather.

A sculpture of a giant hand reaches for the stars in the middle of the Atacama desert.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

A meow-velous tribute to a beloved street cat, made famous on the internet.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

This hidden gem is bathed in beautiful natural light.

This ancient subterranean megalopolis is known for the hot oil traps that were installed above each of its entrances.

The ancient latrines of the Greeks, in all their public glory.

Seven early Christians were sealed into a cave where legend has it they slept unharmed for centuries.

Mediterranean castle on a tiny Turkish island.

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

The ancient abodes are a testament to human ingenuity amid harsh climates.

A charming beach town in Turkey captures all the colors of the rainbow.

Mausoleum and Holy Seat of Antiochus I of Commagene.

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

The best-preserved ancient theater in the world.