Equivalent to an atomic bomb in terms of its destructive power, the Tianqi Explosion is considered one of three major mysteries in recorded history yet to be solved. If you’re into solving puzzles, the others two are a 3,600-year-old event called Mound of the Dead that occurred in ancient India and Russia’s Tunguska Event that occurred in 1908. 

Today, we’re going to tell some stories concerning a cataclysmic explosion that turned much of Beijing to rubble nearly 400 years ago. Historians estimate that over 20,000 people were killed or injured, but the mystery of what happened has yet to be solved.