Ashen Hill Manor was a large manor house in the English countryside. It was erected well before 1665, when Lord Marchwood lived there.
The events following the employment of Erasmus Darkening by Marchwood earned the manor the reputation of being haunted. In reality the malfunction of Darkening's machine led to many people becoming trapped between dimensions over the years.
There were a lot of books in Ashen Hill Manor, among those were The History of Ashen Hill Manor, Secret Tales, Masterpiece Library of Short Stories, Pass It On by Geoffrey Gilbey, Thankless Child by Frank Swinnerton and The Day Before Sunrise by Thomas Wiseman. (TV: The Eternity Trap)
In the 1920s the psychic investigator Harry Price catalogued a 121 different entities within Ashen Hill Manor. (WC: Alien File: Erasmus Darkening)