Each program is introduced and book-ended by author and inventor of the communications satellite Arthur C. Clarke in short sequences filmed in Sri Lanka.

There are also segments on the Antikythera Mechanism (including an interview with Derek J. de Solla Price), the Stone Balls of Costa Rica and the so-called 'Skull of Doom' which dominates the opening credits of the series.

Interviewees for the segment on the Yeti include Don Whillans, Lord Hunt and Eric Shipton.

Lengthy consideration is given to the Patterson–Gimlin film, and interviewees include Grover Krantz – who demonstrates several casts of alleged Bigfoot tracks that he feels bolsters his belief that the creature represents a relative of Gigantopithecus.

Including Mokele-mbembe, giant anaconda, Ameranthropoides loysi as well as sightings and excavations of animals such as the moa and the woolly mammoth.