

At Mexico's Temple of the Sun, Graham experiences the extent of the Mayans' astronomical expertise and investigates their complex calendar system.
From ancient footprints to mysterious earthworks, Graham continues his journey into the past alongside experts and curious minds, including Keanu Reeves.
Graham searches for answers to the questions behind ancient works of art, including 25,000-year-old Amazonian paintings and the megaliths of Rapa Nui.