The British isles. These islands have seen many people come and go. From Roman legions made up of people from far away as Syrian and Iraq and Northern Africa (and yes, there is confirmed evidence that the legions manning Hadrian's wall had people from Syria and Northern Africa), to the invaders from Scandinavia. So it makes sense that these islands would be full of hauntings.
Here are four Haunting's from the U.K one from each individual country as a matter of fact.
The Treasurers House in York, England
In 1953 an apprentice plumber was working in the basement of the Treasurers House when he heard a sound from another time: the sounds of the horns of a Roman Legion. However, he kept working and went up the ladder when a ghostly horse and legionnaire brigade came through the wall. After falling and getting up the curator charged into the room and knew what he'd seen after saying, 'you saw the solders too.'
Carrickfergus Castle, Northern Ireland
Prince William might want to be aware that his title of Baron Carrickfergus comes with a ghost attached. This historic castle in Northern Ireland is haunted by several spirits one of which is called Buttoncap. Buttoncap is said to be a soldier executed for a case of mistaken identity.
Rothiemurchus Forest, Scotland
Back in the days when Scottish Clans ruled the wild north, this was the place where the Clan Shaw had their funerals. The Chief of Clan Shaw still haunts the forest, occasionally challenges hikers and passerby to fight as he still fights for his clan even in death.
The Skirrid Mountain Inn, Wales
The Skirrid Mountain inn is the oldest pub in Wales at over 900 years old. It holds a whole bunch of ghosts from a Hanging Judge and the felons he hung, to a deceased local Clergyman. The inn is famous and a tourist attraction so if you want to. you can go see it.