A gateway to a mysterious network of underground tunnels.

A pocket of Buenos Aires with an unusually high concentration of psychotherapists.

This singular Mexican structure is considered a masterpiece of the Tapatía architectural school.

This concrete amphitheater offers an unforgettable view of one of Mexico's most beautiful canyons.

This structure was moved nearly 40 feet while people continued working inside it.

For this chef, an active volcano is his oven.

A journey through a collection of classic cars and fashionable artwork.

A hidden gem of a museum that lets you search for your own fossils.

Enjoy coffee and cake while viewing antique medical equipment at this unique cafe.

The "Rocky Horror Picture Show" character has a hidden camera that broadcasts people doing the "Time Warp."

Modern art meets modern convenience in possibly the world's most architecturally important public bathroom.

Nature's slip and slide.

Handcrafted thermal spa washes away each night with the tide.

Highly spherical boulders on the shores of New Zealand.

A galaxy of glowworms—larvae of a gnat—hides deep in the belly of these caves.

The explorer Captain Cook may have named it White Island, but the Maori call it Te Puia o Whakaari – The Dramatic Volcano.

These phallic stone spires once served as Tolkien's Paths of the Dead.

This strange geological landscape erupts with sudden bursts of water.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

Taumatawhakatangihangakoauauo tamateaturipukakapikimaungahoronuku pokaiwhenuakitanatahu.

One of the world's steepest streets seems to have houses sliding down it.

A Maori village obliterated by an 1886 volcanic eruption.

This electric green sulphur lake in New Zealand looks like a cartoonish radioactive dump site.

A perfect turquoise lake colored with glacier dust.