
What on Earth?
Experts investigate if a sinister cave in Iceland could hold secrets of alien worlds.

Experts investigate if a sinister cave in Iceland could hold secrets of alien worlds.

Experts investigate a possible response to a message sent to an alien star cluster in 1974.

When satellites spot an odd structure, experts reveal secrets from a strange place.

A strange facility is spotted in Russia; experts investigate if it's hiding evidence of alien life.

Experts use cutting-edge technology to reveal the truth behind sinister mysteries from space.

Circular forest next to a cannibal site; a crater could be evidence of Tesla's doomsday device;.

A 5,000-year-old structure in Ireland; machine that can see back in time; witchcraft in New World.

A site that could be the Garden of Eden; a gateway to hell; shipwreck could be an KGB pirate ship.

Mysteries from geological occurrences to man-made structures as seen by more than 4,000 satellites.

New clues in the hunt for Jack the Ripper; a strange object crash-lands in Antarctica.

A fleet of sunken ships that point to ghosts, cannibals and bloodshed in early America.

Zombie reindeer haunting Norway; strange circles in the sand; a giant streak in the Arctic.

Army of the dead in Siberia; stone giant in a remote desert; Russian doomsday device.

Alien monoliths haunt the coast of England; evidence of a strange creature emerging from the deep.

Strange happenings in the Himalayas could be evidence of a program to turn monks into killer agents.

Revealing how the Mayans vanished; traces of ritualistic drug binges; sex cult of millionaires.

A ghost ship appears on a remote island that holds one of the world's last uncontacted tribes.

Treasure hunters search for a lost Incan city of untold wealth; investigation Cleopatra's gems.

Crypt rumored to hold the Ark of the Covenant; a mysterious ocean monster; tribute to a spider god.

A Stonehenge-like structure may have links to the Nazis; a lake appears in the Sahara overnight.