Home to nearly a third of the world's mud volcanoes, Azerbaijan is home to a messy, bubbling, and sometimes explosive landscape.

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

Tubing through a cave lit with glowworms is a magical underground experience.

Prehistoric park filled with the fossils of dozens of extinct species including Australian megafauna.

This trio of Australian rock spires may have inspired aboriginal legend or just modern tourism.

A massive stairway that almost wasn't leads to one of Australia's most scenic vistas.

Bohol's unusually shaped hills turn brown in the summer months.

A patch of Philippines forest devoted to saving the lives of an emotionally sensitive species of googly-eyed primates.

An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

An eatery in a shallow river where diners can enjoy their meal mere feet from the base of an artificial waterfall.

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

What was once a unique system of urban elevators is turning into a mechanical ruin.

As one of the world's largest hydroelectric dams this plant took two countries to get built.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

Roman ruins top white travertine terraces formed by ancient hot springs.

The most metal church of all time was built in record time because of an international, pious pissing contest.

Ancient serpentine sacrifice holder that has stood the test of time.

A marvel of Byzantine engineering under the streets of Istanbul.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

The original "capsule building" is a masterpiece of Metabolist architecture.

Starship-temple contains 400 tons of drinking water and offers free Japanese lessons.

Gigantic unfinished stupa and the world's 2nd largest bell.