Garregan Castle is a disused fortification in the Kingdom of Evenhold that overlooks the Bay of Lindom. Completed during War of Anharic Succession, the castle was built to house soldiers protecting the western approaches to the city of Southport, while the tower on nearby Garregan's Rock was erected to monitor and fire on enemy vessels approaching the harbor. Neither was ideally placed, and when centuries of erosion began to threaten the cliffside castle, both structures were abandoned around 1120 YA. Improved defenses built closer to Southport now protect its harbor, while a lighthouse on Wether Rock farther out in the bay helps guide passing ships.

Since the castle's abandonment, vampires and other dangerous creatures are said to have occupied both the building and the caverns that run below it.