We delve into ancient mysteries that have remained unsolved for thousands of years.
A mysterious megalithic monument emerges from Spain's watery depths.
Who were the mysterious skeletons found 100ft underground – and why were they there?
How did 500 human skeletons end up in a remote lake high in the Himalayas?
BEST OF 2019: Who's really buried in these intriguing monuments?
What made the Harappan civilisation leave their cities for the Himalayas?
Were the original inhabitants of the Canary Islands really survivors of the lost city of Atlantis?
The Pulemelei Mound in Polynesia offers unique insight into Samoan history
In the south Australian countryside sits a mysterious Aboriginal stone arrangement.