In the distant past, the Haunted Keep was the castle of the Rodemus family. It was abandoned many years ago when the family mysteriously disappeared. It is now rumored to be haunted. Strange lights and sounds are often seen and heard in the ruins by passing townspeople.
Recently, a tribe of goblins has been raiding the countryside. On their last raid they captured a dozen prisoners. The prisoners are all relatives of the player characters, who have banded together to rescue their relatives. The party has tracked the goblins to the Keep or castle, right up to the only door to the east tower.
Most of the Haunted Keep is in ruins. Only two towers remain, connected by a gatehouse, and only the first floors of these towers are still intact. The Keep was built with rough granite blocks, now pitted with age. The door into the east tower is wooden and one hinge is rusted through.

Basic D&D