Viking treasure found in Norway, Maya masks unearthed in Mexico, animal bones discovered beneath the Roman Colosseum.

From the everyday suburban dwelling of BTK Killer Dennis Rader to mad preacher Gary Heidnik's basement pit full of sex slaves, these serial killers' houses are some of the most disturbing places you'll ever see.

From Santa Claus to Krampus, and everything in between, there are dozens of different Santa legends found around the world.

Like many Christmas traditions, evergreens were once used in pagan winter solstice celebrations.

Ancient temple to Demeter found in Crete, Etruscan statues uncovered in Italy, millennia-old branding irons used on slaves unearthed in Egypt.

Ancient Roman theater discovered in Crete, history's first written sentence uncovered in Israel, Stone Age child who may have been buried with a wolf found in Finland.

In 1973, Elmer Wayne Henley Jr. shot and killed Dean "Candy Man" Corll after he had raped and murdered dozens of teenage boys — and after Henley had killed six of them himself.

Go inside the unsolved mystery of D.B. Cooper, the infamous skyjacker who may have been a paratrooper and ex-convict named Robert Rackstraw.

Trophy heads from human sacrifices found in Peru, face of 19th-century "vampire" reconstructed, 85-year-old explorers' cameras recovered in the Yukon.

A holiday of airing grievances and decorating with a bare aluminum pole, Festivus was popularized by "Seinfeld" in 1997 — but it actually began decades before that.

A half-goat demon said to be the son of the Norse god of the underworld, Krampus punishes naughty children at Christmastime — and drags some to hell.