Castles of Hârn is a module detailing eight castles around the island of Hârn. Each article consists of a color local map, interior plans and key to special features of the settlement.

The castles included are:
Geda - A thriving town in the small kingdom of Chybisa
Geshtei - A province capital in the Thardic Republic
Gythrun - A port on the mainland coast of Melderyn
Ithiko - The birthplace of prophet Balsha in Rethem
Lorkin - A haunted castle in Orbaal
Qualdris - The seat of the disappeared Earl of Osel in Kaldor
Quimen - A keep of the savage female kinghts of Crimson Dancer
Sarkum - The castle of the most poweful noble in Kanday