Wales was famous for its coal mining, in the Rhondda Valley, the South Wales Valleys and throughout the South Wales coalfield and by 1913 Barry had become the largest coal exporting port in the world, with Cardiff as second, as coal was transported down by rail. Northeast Wales also had its own coalfield and Tower Colliery (closed January 2008) near Hirwaun is regarded by many as the oldest open coal mine and one of the largest in the world. Wales has also had a significant history of mining for slate, gold and various metal ores.