Mottes were mounds, usually artificially constructed, with a defensive wooden or stone castle tower built on the flat top. They were introduced into Scotland by Norman settlers in the 12th century. The best examples in the Gryffe area are Denniston Motte and Castle Hill Motte (alternatively designated as Ranfurly Motte) which is situated on Old Ranfurly Golf Course. Both would have been topped by towers.
Castle Hill Motte (opposite GZ at the flag pole) on Old Ranfurly Golf Course is more widely known and is regarded as the best example of a motte in Renfrewshire. The mound itself is not man-made. It sits on the edge of a five metre high north-facing natural scarp and is surrounded on the other sides by a rock-cut man-made ditch 3-4 metres wide and up to 1 metre in depth. The ditch has been destroyed on the SW by a golf tee, and on the west the ditch has been replaced by the steep, natural slope. The motte is about 18.0m wide across its flat top, which appears to have shallow rectangular depressions dug into it, possibly indicating a former building, but more probably of recent origin. There is an old mutilation on the west.
Finds from Castle Hill Motte, including Samian pottery (Roman), a bronze key, green glazed pottery, bones, charcoal and whitening material were displayed at the Palace of History Exhibition in Glasgow in 1911