Scientists often work on guesswork and theories until proven wrong, and many mysteries still puzzle them. Archaeologists discovered a 5,000-year-old tomb beneath the Hellfire Club in Dublin, Ireland, which may have caused the building's haunting rumors. The Neanderthals were capable of creating complex structures, such as the ring structures found in the Brunel cave in France, suggesting abstract or ritualistic behavior.

A 5,000-year-old needle made of animal bone was found in a cave in Siberia, believed to be the oldest sewing needle in the world and made by the Denisovans.

A 17th-century Dutch trading vessel, called a flute, was discovered well-preserved at the bottom of the Baltic Sea by Finnish divers in 2020, with no visible damage to the ship. The Grobbel man, a mummified body found in Denmark, is a unique exhibit in the Moesgaard Museum.