Ratho Quarry
This Late Carboniferous igneous rock, dated accurately to 307 million years, is part of a wider igneous intrusion that outcrops in sites such as Queensferry, Stirling and beyond. The former quarry has since been adapted to become the Edinburgh International Climbing Arena. Good exposures of columnar jointed quartz-gabbro, a coarse grained rock derived from magma, are seen in the adjacent M8 road cutting as well as in the old quarry. The Union Canal was once the main artery to take the rock by barge into Edinburgh.