Is it a Ghost?

A man was visiting Eynsford Castle in Kent with his 12-year-old son.  He took pictures for his son's homework project.  They were learning about the history of the castle.  When Jon Wickes looked at the pictures he took, he found one that was a bit spooky.  Even though him and his son were the only ones at the castle, a figure appeared in one of the photos.  A paranormal investigator went to the castle to see if the black cloaked figure could've been caused by a natural phenomenon.  Nothing was found.  Most people believe it to be the ghost of a monk that has been seen before in the castle.  Source: Mirror