Watch World's Scariest Hauntings

30 miles north of Prague in the countryside of the Czech Republic, sits Houska Castle, one of the most mysterious fortresses in the world. The 13th century castle wasn't built to keep people from getting in, it was built to keep something from getting out.

Built in 1832 in New York City, the Merchant's House Museum is a time capsule of 19th century Manhattan. Some say the Tredwell family, who lived in the house for nearly 100 years, are still in residence.

Built in 1779, Bodmin Jail in Cornwall has housed many notorious criminals, some of whom were put to death on the grounds. Some 240 years later it is now a museum and soon to be a hotel complex. But it's believed that many of the spirits have never left the building.

Located in rural North Wales, Plas Teg is a 17th century Jacobean mansion that literally translates into English as Fair Mansion, but many of the spirits that reside here are more foul than fair.

Standing since the 12th century in Rye, on the south coast of England, The Mermaid Inn once played host to the notorious band of smugglers known as the Hawkhurst Gang. Some 500 years later, paranormal enthusiasts believe the bootleggers still haunt the medieval building.

Under the cobbled streets of one of Europe's most haunted cities you'll find the Edinburgh Vaults. Dating back to the 1700s, murder, misery and unnatural death was rife in the slums of Scotland's historic capital city. Since the vaults were rediscovered in 1985 they have become a hotbed of paranormal activity.

The cosmopolitan district of Griffintown in Montreal, Canada has a dark history. Many Irish immigrants who arrived in the 18th century died from diseases and murders were rife. As gentrification of the area continues, the constant construction work has awoken the dead.

Built in 1952, Kelvedon Hatch bunker was designed as a safehouse for the British government in the event of a Nuclear attack. Nestled deep in the Essex woodland, it was hidden from the world and only revealed to the public in 1992 when it was decommissioned.

With tales of bloodshed and slaughter, Leap Castle wouldn't look out of place in a Hollywood fantasy world. But the stories of death and torture at the medieval Irish stronghold are very much real.

Being situated on an ancient pagan burial site and a Ley Line intersection in Gloucestershire, England, it's no wonder the Ancient Ram is one of the most haunted houses in the world.