A sunken 'pyramid' near Taiwan may rewrite everything we thought we knew about the ancient world. Sitting just 82 feet below sea level near the Ryukyu Islands of Japan, a mysterious object called ...

From geologic puzzles of deep time to unsolved crimes of the 20th century, here are 15 of history’s greatest mysteries—most of which remained unsolved to this day. 1. Where is Cleopatra’s tomb?

Göbekli Tepe, a 11,000-year-old temple in Turkey, predates farming and rewrites history with its massive carved pillars, ...

Read the task aloud to students: History is filled with unsolved mysteries. Your task in this research project is to choose one of those mysteries and present a plausible theory to explain it.