From 1961 to 1971, the U.S. used the herbicide and defoliant Agent Orange in Vietnam, leaving behind millions of victims with deadly diseases and birth defects.

Built between 9500 and 8000 BCE in present-day Turkey, Göbekli Tepe is a Neolithic place of worship that predates Stonehenge by over 6,000 years.

An 18th-century French showman, Tarrare could eat enough to feed 15 people and swallow cats whole — but his stomach was never satisfied.

On a busy Saigon street in June 1963, Buddhist monk Thích Quảng Đức lit himself on fire and set off a chain of events that led to America's involvement in the Vietnam War.

Despite his mythic handicap, Ivar the Boneless was the most fearsome Viking of his time and conquered England with his heathen army.

Known informally as the Japanese mafia, the Yakuza are a 400-year-old criminal syndicate that carries out everything from human trafficking to real estate sales.

Reinhard Heydrich had many nicknames: "the Blond Beast," "the Hangman," and "the Butcher of Prague" — but none of them quite captured just how ruthless he was.

When Prohibition finally ended with the ratification of the 21st Amendment in 1933, America kicked off the biggest impromptu party the country had ever seen.

Groupies were more than just the sex that came with music stardom — they were muses who left their marks all over the history of rock music.

Jack Unterweger went to prison for murder, then found fame as an author — before strangling several women to death in Austria and Los Angeles between 1990 and 1991.

The enormous ocean sunfish known as the Mola mola can grow to be 5,000 pounds and 14 feet long, making it the world's largest bony fish.