Most of the surface buildings have been removed, and apart from a winding wheel outside Radstock Museum, little evidence of their former existence remains. Further west, the Brendon Hills were mined for iron ore in the late 19th century; this was taken by the West Somerset Mineral Railway to Watchet Harbour for shipment to the furnaces at Ebbw Vale in south Wales. The county has a long tradition of supplying freestone and building stone. Quarries at Doulting supplied the freestone used in the construction of Wells Cathedral. Bath stone is also widely used. Ralph Allen promoted its use in the early 18th century, but it was used locally long before then. It was mined underground at Combe Down and Bathampton Down Mines, and as a result of cutting the Box Tunnel, at various locations in Wiltshire, including Box. Bath stone is still used today, on a reduced scale; but more often as a cladding, rather than a structural material. Further south, Hamstone is the colloquial name given to stone from Ham Hill, which is also widely used in the construction industry. Blue Lias has been used locally as a building stone; and as a raw material for lime mortar and Portland cement. Puriton up to the 1960s had Blue Lias stone quarries, as did several other Polden Villages. Its quarries also supplied a Lime mortar and Portland cement factory at Dunball, adjacent to the King's Sedgemoor Drain. Its derelict, early 20th century, remains were removed when the M5 motorway was constructed in the mid-1970s. Keinton Mandeville was also heavily involved in quarrying; the village's quarries are now abandoned, but they are still remembered in the name of a Public House. Quarrying of blue lias is still undertaken at Charlton Mackrell and Charlton Adam. Since the 1920s, the county has supplied aggregates. Foster Yeoman is Europe's large supplier of limestone aggregates, with quarries at Merehead Quarry. It has a dedicated railway operation, Mendip Rail, which is used to transport aggregates by rail from a group of Mendip quarries. Tourism Much of the county is scenic and unspoilt. Tourism is a major industry, estimated in 2001 to support around 23,000 people. Attractions include the coastal towns, from the west to the north east, Minehead, Watchet, Burnham-on-Sea, Weston-super-Mare, Clevedon and Portishead, with their various piers and beaches. Inland the county includes part of the Exmoor National Park, the West Somerset Railway (a heritage