For centuries, man has yearned for an earthly paradise, and no place better encapsulates this desire than Shangri-La - but was it ever real? The tale of an earthly paradise is among the most enduring myths in the world. From Sumerian epic to the 'islands of the blest' in Celtic literature, it has been a recurring theme through many bodies of literature and for thousands of years. Not surprisingly, then, modern people have also been drawn to the dream of a lost paradise where the ravages of time and history have been held back, where human beings live in harmony with nature, and where the wisdom of the planet is saved for future generations. In other words, to a Shangri-La.

The Greek tale of Jason and the Golden Fleece has been told for 3,000 years. It's a classic hero's quest tale - a sort of ancient Greek mission impossible - in which the hero embarks on a sea voyage into an unknown land, with a great task to achieve. He is in search of a magical ram's fleece, which he has to find in order to reclaim his father's kingdom of Iolkos from the usurper King Pelias. Michael Wood discovers a story of heroism, treachery, love and tragedy that would make Hollywood proud.

In 335 BC Alexander of Macedonia set off on an expedition to conqueror the world. The voyage of Alexander the Great covered more than 22,000 miles in ten years, from Greece to India and back, through some of the most difficult and unforgiving terrain. Michael Wood was hot on his trail, following, as closely as possible, in the footsteps of Alexander and the army that he drove to achieve the impossible. In this programme: the Lebanese city of Tyre, scene of Alexander's most desperate battle; the Palestinian legend of `Two-Horned Alexander'; and the Egyptian oasis of Siwa, where Alexander was proclaimed pharaoh and son of God.

The final leg takes him from the Khyber Pass through Pakistan to the Punjab, where Alexander's army mutinied and he was forced to return across the Makran Desert to Babylon, where he died at only 32 years of age.

The word Anunnaki means "princely seed" or "princely blood". The idea is that the Anunnaki were direct creations of Anu, who was regarded as the father and king of the gods. Ancient Aliens: "In the ancient texts of Sumeria we have descriptions of these being descending from the sky called the Anunnaki. The term Anunnaki means 'those who from the heavens came."

The Nazca Lines of Peru have been an important part of the Ancient Astronaut theory since its beginning. Originally Von Daniken claimed that the lines were kind of a UFO runway, or a type of alien airport, where the alien craft landed and took off. The idea that it was an airport makes no logical sense, and the symbols and rituals which were a huge part of the Nazcan culture more than explain the so called Nazca lines.