[private]
Mine was the old headquarters of the Vampire Hunter Association. In the past the dungeons were used to house imprisoned vampires. [Hint #1, just not an obvious one.]
The school was created by a retired vampire hunter as a way to promote coexistence. At night the vampires used the same classrooms the humans used during the day, so my school was crawling in vampires once the sun went down.
They do a good job of acting peaceful though, like I said. I think a hellmouth would be a lot more chaotic.