Perhaps they never even existed. Yet the hunt for these five legendary treasures will never end — at least not until they are found.
It's an age-old dream: Getting rich in one fell swoop without having to work for it — despite your humble origins.
Such rags to riches fantasies are as old as time and often involve the accidental discovery of hidden treasures. Some come true: like when a German student found a 17th century painting hidden in an old sofa bought at a flea market that sold for near €20,000 ($22,700).
Across Europe, long-rumored lost treasures are still waiting to be discovered. Their whereabouts are as mysterious as they are legendary.
Read more: Fabled Nazi gold train: Is the hunt over?
One persistent hidden treasure myth is the Russian Tsar's family fortune, some of which was lost during the 1917 revolution. Allegedly, a large part of the Nicholas II’s gold reserves were to be taken out of the country but the booty never crossed the border.
The location of the gold went with Tsar Nicholas to his grave after he and his family were murdered by the Bolsheviks. It's said that the gold bars are lying at the bottom of Lake Baikal.
The medieval Nibelung treasure myth is even more nebulous.
Here 144 wagons of gold from King Nibelung were sunk in the Rhine River in western Germany after the death of dragon slayer Siegfried. But historians cannot lend credence to this myth, which nonetheless persists — as does the hunt for the gold's location.
Discover five lost treasure legends in the latest High Five picture gallery above.