A French-Colonial era collection of taxidermy and wet specimens, secreted away in the National University of Hanoi.

World's largest cave was only discovered in 1991, and now offers tours to the public.

From prostitutes to soldiers to business men, the dead in this graveyard are a microcosm of Singapore's history with Japan.

The cuisine at this Sheepshead Bay spot tells the story of a displaced Muslim Chinese community.

This charming, hidden guild museum holds some 700 years of crossbow history.

A metal ring in the middle of the road marks the exact spot where the Soviet satellite crash-landed in 1962.

This former Soviet military base has over 10 original aircraft and an enormous amount of memorabilia on display.

4,000 monkeys used for medical testing on an island off of South Carolina.

In paradise, feral pigs have claimed an island all to themselves.

An eccentric aristocrat brought these Australian natives to their current Scottish home.

It was meant to help transport wounded soldiers to a secret underground hospital.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

This overlooked street light once served as a KGB dead letter box.

A plaque marks the house in Stockholm where the French philosopher René Descartes lived up until his death.

A tombstone on the grounds of the royal castle marks the burial site of a Swedish king's beloved dog.

Stumps of an Ice Age forest, visible only at low tide.

Complete town of 5,000 living out at sea on the world's first offshore oil platform.

Azerbaijani ghost town, decaying after a war left it an armed forces buffer zone.

Spring that emits water and fire at the same time is said to have remedial properties, and sparked its own religion.

A shrine of fire worship built on top of a natural flame.

Resonant stone, that has been played since prehistoric times.

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

Mysterious hillside with a continuously burning natural fire.