Above the town of Grange over Sands is a limestone escarpment of international importance. The Carboniferous limestone pavement hosts many wild flowers in the spring and is an area popular with walkers. The Carboniferous limestone was laid down around 340 million years ago in a warm shallow sea that covered much of north west Europe. The rocks often consist of the fossilised remains and fragments of animals alive at that time such as shells, and corals. Since Carboniferous times much of the white limestone has been removed or dissolved away. As recently as 15000 years BP glaciers scoured the rock and as the ice retreated, the meltwaters dissolve the surface exposures still further leaving what is known as limestone pavement.