Margrove Park Ironstone Mine is at NZ 653155. The upcast shaft was extended above surface as a chimney for an underground furnace. Probably after the Coal Mines Act of 1911 a surface fan was installed and the chimney raised with a pulley wheel fitted for a cage in this shaft. After closure in 1924 both shafts and drift were filled but the chimney and wheel remain, although the landowner removed the pulley then replaced it in 1989 so it is no longer aligned with the site of the winding engine.

Calcutta Colliery was at SK 420169. The headgear is a relatively modern steel erection with four well-splayed legs. Of more historic interest is the huge engine house alongside which housed the pumping engine at this shaft from 1877 until about 1947. I hope this building is Listed.