What are the worst documented Hauntings in history?

There are many documented cases of the supernatural – and especially hauntings, being possessed, and other paranormal activity have been reported over the years.

What are some of the most storied hauntings – religious ones are especially interesting.

The Quarantine Station on North Head in Sydney, NSW, Australia has experienced sightings and stories of the supernatural (ghosts particularly) for over a century. See http://www.castleofspirits.com/quarantine.html for a full overview of the Quarantine Station and its history.