From the viewpoint at Millom Rock Park you can look out over the bustle of a working quarry where powerful diggers, dump trucks and wagons work the quarry floor. As you gaze into the depths of Ghyll Scaur Quarry you are looking back 450 million years into the heart of a vast volcano that once covered most of the Lake District. Over several million years, the lavas and tuffs ejected by the volcano formed rocks up to eight kilometres thick. Large volumes of hot molten rock and ash were deposited in catastrophic explosive eruptions. Smaller eruptions occurred when the molten rock interacted with cold groundwater. The hot volcanic ash cooled into a compact rock called tuff. When crushed, this is ideal for surfacing roads, motorways and airport runways.
The quarry is managed by Aggregate Industries and produces high quality aggregates for anti-skid surfaces and roadstone. The vast workings are up to 50 metres deep and cover around 30 hectares. An estimated eight million tonnes of roadstone have been extracted from the quarry since it opened in the 1930s. That's enough to surface a motorway all the way from Millom to Milan.
CAUTION! Although the Rock Park is separated from the Quarry by secure fencing, visitors should take care and keep away from steep drops and rock faces. Children must be supervised at all times. Access to the quarry is strictly prohibited. The Park will be closed during blasting for safety reasons.