Archaeologists have discovered ancient drawings thought to have been created by a long lost civilization.
These half-bird, half-lion creatures of myth and folklore were long thought to have been inspired by Protoceratops.
The Vatican is thought to be in possession of a wealth of rare documents concerning unexplained phenomena.
A planet thought to be the real-life equivalent of Spock's homeworld Vulcan might not actually exist after all.
The wreck of the San Jose, a 300-year-old Spanish galleon, is thought to be filled with gold and jewels.
A lot of strange tactics were thought up during the Second World War, but this is perhaps one of the strangest of them all.
Saturn's icy moon is thought to be home to an ocean of liquid water, meaning that it might also be home to alien life.
The inventor and engineer picked up a mysterious signal in 1899 that he could not find an explanation for.
When it was first discovered 20 years ago, it was thought that Apophis had a relatively high chance of colliding with us.
A fishing crew has reportedly recovered what is thought to be the remains of another spy balloon in the waters off Alaska.
This striking yellow and black bird, which hadn't been seen for 20 years, was rediscovered during an expedition to Africa.
The intriguing find suggests that metalworking techniques were more advanced than we thought 3,000 years ago.
For decades, the fossil of a lizard found over 90 years ago was thought to exhibit evidence of preserved soft tissues.
An undersea mapping firm has captured a sonar image that is thought to show the late aviator's plane.
If you think you are having a bad day, spare a thought for this guy...
For decades, Neptune was thought to be rich blue and Uranus was thought to be pale green.
It is now believed that some of the fossils once thought to be young T. rexes are actually adults of a separate species.
For centuries, rogue waves were thought to be little more than myth, but that all changed three decades ago.
These huge prehistoric carnivores were long thought to be close cousins of the modern day gray wolf.
Archaeologists have unearthed the remains of an ancient fortress built by hunter-gatherers in Siberia's Lower Ob' region.