Watch Arthur C. Clarke's Mysterious World

A collection of mysteries in this season finale includes the moving stones of California's Death Valley, entombed toads and ball lightning.

Investigations into mysteries of celestial bodies such as an unknown civilization on Mars, the lost planet Vulcan and the identity of the Star of Bethlehem.

Sightings and excavations of the giant anaconda, the woolly mammoth and the tale of the De Loys' ape, an unknown primate named after the Swiss geologist who photographed it in 1920.

This episode looks into one of the most ubiquitous mysteries of our lifetime - reported sightings of "flying saucers."

Clarke devotes this episode to a story old as man: something falling to Earth from the sky. The cases vary and so do the possible solutions as to how and why strange or unlikely objects fall out of it.

Arthur C. Clarke examines theories behind the pre-historic mysteries of stone circles and standing stones in Britain.

We explore the largest naturally occurring explosion, which sent shock waves around the world and is known as the Tunguska event of 1908 in Siberia.

Tales of gigantic monsters lurking in more than 70 lakes around the world, such as: Nessie in the Loch Ness, Scotland, and Ogopogo in the Okanagan Lake, Canada.

Mystifying geoglyphs, giant pictures covering large areas on the ground, appear across the globe, many created by ancient peoples. They only become recognizable at great distances or are situated away from the common sight of man.

This episode looks at evidence for both Bigfoot in North America and the Yeti, or abominable snowman, in the Himalayas.

This episode explores extraordinary technologies from ancient civilizations that were either ahead of their times or forgotten in the ruins of history.

Arthur C. Clarke dives into the mysteries of the deepest and darkest realms of earth. Encounters with the great sea serpent, the giant squid, the giant octopus and the megamouth shark are explored.

Viewers embark on a journey with Clarke as their guide through mysteries of this world. Clarke introduces the various themes that will be explored in the series.