Hagglethorn Hall is an old Scottish castle brought to America brick-by-brick by Sedgwick Jones, the First Earl of Hagglethorn.
History
The New Scooby-Doo Movies
Season one
It was supposed to be a tourist attraction, but a Haunted Horseman and a Moat Monster were scaring people away. (The Haunted Horseman of Hagglethorn Hall)
Subterranean cave