The library appears to be missing information about this subject.
Dark Haven is home to a Minor Ritual circle of the same name, aligned to Evil & Necromancy.
Dark Haven is home to Tarantulas Ancestral Grove, and is currently being transformed into a Citadel of Faith for the Tarantula Pantheon
Dark Haven was once the seat of Clan Kerithrion, and played host to many aspects of law within the Underdark. The history of this is evident around the city, although it is no longer home to Clan Kerithrion.
