Fortescue's Shaft, North Engine House, on Site of Grenville United North Mine

Fortescue's Shaft, North Engine House, is a derelict pump engine house located on the site of the former Grenville United North Mine, likely built in the late 19th century. The structure is constructed from large granite rubble, with quoins and a bob wall made of granite blocks. It features window arches of yellow brick and a brick upper stage for the chimney, which is now roofless. The building has a rectangular plan oriented north-south, with the bob wall on the south side and a circular chimney attached at the north-east corner.

The engine house is a large structure with three stages above a high plinth. It includes a narrow segmental-headed driver's window in the bob wall, a large round-headed cylinder door in the rear wall, and a narrow square-headed doorway on the west side near the bob wall. Various smaller round-headed windows are present on both sides, along with some tie-plates. The tapered cylindrical chimney has an arched opening on the west side of its base, and there is no cornice at the junction with the brick stage, which is damaged at the top. This building serves as a functional partner to the winding engine house located approximately 50 meters to the south, creating an impressive group of structures. Historically, it is one of several mines that exploited the Great Flat Lode.