Hidden inside the world's castles and mansions are secrets waiting to be revealed. What remarkable tales of mystery and adventure transpired within their walls?

Could there be life beyond our planet? Extraordinary NASA footage and ground-breaking interviews with astronauts and scientists investigate potential sightings of UFOs.

Could there be life beyond our planet? Extraordinary NASA footage and ground-breaking interviews with astronauts and scientists investigate potential sightings of UFOs.

Former Colorado law enforcement officer Chuck Zukowski and his son Daniel investigate UFO-related cases that the authorities usually ignore. They search for definitive proof of UFOs along America’s infamous Alien Highway.

Former Colorado law enforcement officer Chuck Zukowski and his son Daniel investigate UFO-related cases that the authorities usually ignore. They search for definitive proof of UFOs along America’s infamous Alien Highway.

A team of outdoorsmen is taking on the challenge of exploring the Alaska Triangle to uncover proof of the cryptic creatures thought to be living there.

A team of outdoorsmen is taking on the challenge of exploring the Alaska Triangle to uncover proof of the cryptic creatures thought to be living there.

Nick Groff and Katrina Weidman spend 72 hours confined to the most haunted locations in the United Kingdom in search of groundbreaking evidence of the paranormal.

On The Dead Files, physical medium Amy Allan and retired NYPD homicide detective Steve DiSchiavi combine their unique and often conflicting skills to solve unexplained paranormal phenomena in haunted locations across America.

On The Dead Files, physical medium Amy Allan and retired NYPD homicide detective Steve DiSchiavi combine their unique and often conflicting skills to solve unexplained paranormal phenomena in haunted locations across America.

Three best friends investigate Americas's most haunted locations.

Police officers, paramedics and other first responders reveal their true encounters with the paranormal while on duty. Not only do these cases defy explanation, they terrify even the most seasoned of men and women who have devoted their lives to serve and protect the living.

After a spike in unusual emergency calls in Morgan City, Louisiana, the town's mayor and his chief of police recruit a team of paranormal experts to investigate the bizarre supernatural activity.

They may be known as the first family of darkness, but legendary rocker Ozzy Osbourne and his wife, Sharon Osbourne, are borderline skeptics when it comes to the paranormal. Determined to convert his parents into full-fledged believers, Jack Osbourne shares the craziest, most jaw-dropping supernatural activity ever caught on camera.

Paranormal explorer Dakota Laden takes his sister and best friend on a cross-country road trip to face their fears at the most haunted locations in America.

Three best friends investigate Americas's most haunted locations.

A team of outdoorsmen is taking on the challenge of exploring the Alaska Triangle to uncover proof of the cryptic creatures thought to be living there.