British climbers Andrew Irvine and George Mallory attempted to scale Everest in 1924 but died during their ascent. It remains unknown if they reached the summit before their deaths.
The ship Mary Celeste was found abandoned and adrift with no sign of its crew, leading to numerous theories about their mysterious disappearance.
A 600-year-old book filled with undeciphered text and illustrations, the Voynich Manuscript's meaning and origin remain unknown despite many attempts to decode it.
Fossils of "Peking Man" were lost during their transport to the U.S. in 1941, and their location remains a mystery, though new related artifacts are still being discovered.
The tomb of Alexander the Great, believed to be in Alexandria, has never been found. Its exact location and condition remain one of history's great unsolved mysteries.
The legendary King Arthur's existence is debated, with no definitive evidence to confirm whether he was a real historical figure or purely mythical.
The Roanoke Colony's inhabitants vanished without a trace, leaving behind the word "CROATOAN." Their fate is still unknown and remains a major historical mystery.
Infamous pirate Captain Kidd claimed to have buried a vast treasure, but it has never been found, leaving its location and existence uncertain.