Much of the Industrial revolution in the United Kingdom began in Birmingham and the Black Country area of West Midlands. The Industrial Revolution is thought to have begun when Abraham Darby substituted coke in the place of charcoal to smelt iron, at his Old Furnace. The Black Country may be regarded as the world's first industrial landscape, while nearby Ironbridge Gorge claims to be the Birthplace of Industry. The world's first cast iron bridge in 1779 spans the Gorge. The first self-propelled locomotive to run on rails in 1803 at Coalbrookdale, was built by Richard Trevithick. The first iron rails for horse-drawn transport, were made at Coalbrookdale in 1768 by Richard Reynolds at Ketley Ironworks. Iron rails only became widely successful in 1820 when made out of wrought iron at Bedlington Ironworks in north-east England.