Quests of Doom 4

Nightstone Keep is a location-based, Swords & Wizardry adventure for characters of 4th to 6th level, centered on a ruined, long-disused stone keep in a temperate wild forest area (possibly not far off a caravan road or forest trail). If you are using the Lost Lands campaign setting, Nightstone Keep is located in the northeastern extent of the Unclaimed Lands where they extend between the southern reaches of the Forest Kingdoms and the Glimmrill Run.

The Unclaimed Lands are detailed in LL5: Borderland Provinces by Frog God Games.

For Fifth Edition.