Llancaiach Fawr is a tudor manor house in Rhymney Valley, Wales. It is best known today for being the home of Colonel Edward Prichard, who hosted King Charles I there in 1645.

But the history of the house dates back much earlier than that, with some estimates putting its construction in or around 1530. An investigation on the Channel 4 archaeological series Time Team gave a much later date after dendrochronology tests dated the roof timbers to between 1548 and 1565.

But regardless of when the current manor house was built, the site itself traces its history even further back, having once been the site of a medieval building, parts of which may have been incorporated into the current building and may still stand today.

In the centuries since, the house has developed a reputation for paranormal activity, with historical interpreter Lee Jessup suggesting that the building is one of the most haunted locations in Wales, if not the whole country.

According to Jessup, the most notorious spirit belongs to Mattie, a housekeeper who lived in the manor house in the late 18th and early 19th centuries. The legend says that Mattie died after being burned in an accident, and her sorrowful spirit has haunted her bedroom ever since.

The original source of this information seems unknown, though, and it's not certain that Mattie ever existed, although many have claimed to have experienced her presence.

Jessup shared one particular example with BBC news, where he spoke of a visit from the South Africa under-21 rugby team, who were visiting wales for a friendly match and were offered a tour of the house.

"As they went into Mattie's room, the captain—who must have been 6' 8", he was an enormous fella—just broke down in floods of tears with no explanation," Jessup explained.

"As soon as he left the room again, he was fine—he was greatly embarassed by it."

In 2003, the LivingTV series Most Haunted visited Llancaiach Fawr for one of their investigations. During a tour of the house, medium Derek Acorah claimed to have contacted the spirit of a buxom governness called Martha, who worked for the Prichard family.

According to Most Haunted's research, Mattie and Martha are one and the same, although Acorah's claims that she was employed by the Prichards is unsubstantiated and the two are believed to have lived at different times in the house's history.

Another common occurrence at Llanciach Fewr is footsteps upstairs, often so heavy that plaster has been known to fall from the ceiling.

One person to have witnessed this first hand is Ed Williams. Prior to its sale to Rhymney Valley District Council, Llanciach Fewr was Wiliams's childhood home, and he reports hearing the ghostly footsteps while watching TV.

"I regularly heard four distinct and loud footsteps above me," he said, "if I had to guess, I would say male."

Williams never investigated the footsteps further. "As far as I was concerned, as long as they didn't bother me, I didn't bother them."

Williams recalls further odd happenings in his interview with WalesOnline. He once saw a man in a Victorian outfit rush past him. Williams was helping with a function that day and when he told his story to the other staff, they were all shaken that a apparition appeared in broad daylight on a summer's day.

"When I was a teenager," Williams continues, "I decided to produce a ouija board."

Using a glass and hoping to see a spirit spell out a message, Williams and his friends were horrified when the glass instead shot across the room and smashed.

One of the most common experiences recounted by guests to the house is the presence of a child spirit. Guests have reported childish noises, such as laughter, when spending time in the house.

During Most Haunted's investigation, Acorah even claimed to have contacted the spirits of two young boys.

There is supposedly more to this than just rumour, though, as a death is said to have happened in 1906 when a young boy fell from a high window. No record of this death seems to be available online, though, except for those that heard the story through word of mouth, so whether this story is true is not entirely sure.

Lee Jessup, unfortunately, has never seen the child ghost first hand. "I've heard footsteps when somebody claimed to have seen him behind me," he told BBC News.

"I've seen enough in this house," he continued, "to make me believe something exists."

More recently, numerous witch marks were discovered in the building. Not to be confused with witch's marks, which are signs on a person's body said to suggest they are in league with the devil, witch marks are instead symbols carved into a building in order to ward away witches, similar to other protective symbols, such as the evil eye.

In Llancaiach, the marks have been found carved into several pieces of wood throughout the building, and it's possible they were carved during the original construction of the building.

These marks are a reminder that regardless of whether anything truly supernatural has happened at Llancaiach Fawr, there's certaintly a rich history of believers who have stepped foot inside this mysterious house.