The Grey House is located in Trewissick, Cornwall. It belongs to Captain Toms but Drew Family and their friend Merriman Lyon live in it during Summer Holiday in the events of Over Sea, Under Stone. The house sits midway up a sloping hill above the harbor and the center of town. It stands out from the other houses like a narrow tower. It has three rows of windows and a gabled roof. It is painted a dark grey but the door and window frames are bright white. The roof is a high arch and a blue grey color. The house faces out over the harbor. During the Drew's stay, Mrs. Palk is their housekeeper.