The land uses of any region depend on the underlying geology which influences the soil types. In the Clwydian Range, lead and spar minerals have been mined in the past, and limestone quarried from Llantysilio Mountain, Ruabon Mountain and Minera Mountain near Wrexham. The Minera Limeworks were once the largest lime workings in North Wales. Later, road building stone was extracted but the quarries closed in 1992. Coal mining in the North Wales Coalfield ceased in the second half of the twentieth century but used to be a large source of employment in the area. The main products being manufactured in industrial east Clwyd include aircraft components (Airbus), engines (Toyota), paper (Shotton Paper) and steel processing, and the port of Mostyn builds and supports offshore windfarms.