Castle of Mey (Barrogill Castle), Scotland

Haunted castles don't come much more modern than this. The Castle of Mey or, as it was originally known, Barrogill Castle is not a medieval fortification but was built in the 16th century by George Sinclair, the 4th Earl of Caithness. It is the daughter of his son, the 5th Earl, who haunts the castle.
The story goes that Elizabeth Sinclair fell in love with a ploughman who worked on a local farm. Her father was horrified that she should consort with a 'commoner'. So he imprisoned her in a room at the top of the castle's tower to prevent her from seeing him.
Some people say that one day she leaned too far out of a window to try and catch a glimpse of her lover working in the fields and that she fell to her death. Others say that she was so unhappy that she threw herself from the tower window.
Whatever the truth is about her demise, today the so-called 'Green Lady' can sometimes be seen sadly drifting around the castle. The place that she is most often observed is the tower room in which the lovelorn girl was imprisoned.