Delve into the most convincing evidence that the planet has been visited by extraterrestrial life forms, from alien encounters in ancient texts to modern-day UFO sightings and the secrets of Area 51.

Some of the most mysterious monsters and mythical creatures that may inhabit this earth, including vampires, Bigfoot and the Loch Ness Monster.

Some of the world's most sacred sites, including the Great Pyramid of Giza, Chartres Cathedral and Masjid Al-Haram.

People who defy the laws of physics and perceptions of reality, from exceptional feats of endurance and miraculous recoveries to psychic abilities and exorcisms.

Mysterious writings, images and relics from the past, including the Nazca Lines, the Voynich Manuscript and the Crystal Skulls.

Paranormal phenomena that baffles experts around the world, from ghostly encounters and spectral curses to spontaneous combustion and the mysterious Hum.