Deadly scalding and one of the largest hot springs in the world.

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

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

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

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

The platform atop this verdant volcano was built with the help of a royal elephant.

A crumbling hospital from the 1850s on Roosevelt Island.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

These abandoned ruins in the middle of Jaffna have withstood centuries of tumultuous power struggles.

The remains of a 37,000-year-old prehistoric society were discovered in this mammoth cave, one of the largest in Asia.

One of the few places where inexperienced snorkelers can spot a shark.

An ancient stone fortress considered by many to be the eighth wonder of the world.

Huge herds of Asian elephants can be seen walking, bathing, and just chilling at this Sri Lankan park.

This ancient structure is widely thought to be the oldest intact pyramid in the world.

Ozymandias’ time-keeping temple.

An ancient city exhumed from the depths of the ocean.

A spectacular cave and a beguiling lake.

Dramatic sea stacks adorn the coast of this small village on the Adriatic coast.

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

A hiking area billed as a possible home to Bigfoot.

A collection of human remains, animal body parts, and other macabre curiosities all legally for sale.

Legend says that this short Canadian tunnel still holds the dying screams of a girl who burned alive.

This natural sea cave hides a small wonderland of natural turquoise beauty.

The remains of a Canadian train crash are now mouldering beneath layers of rust and graffiti.