Swansea Valley yr Ogof Caves, claimed to be the largest show cave complex in Western Europe. South of Abercrave, the valley was formerly a region of heavy industry including coal mining and iron-making and there is plenty of the industrial heritage surviving; the Swansea Canal was built along the valley in the late 18th century to serve the nascent local industries. In 1878 opera singer Adelina Patti made her home at Craig-y-Nos Castle. Swansea Valley The Swansea Valley (), one of the South Wales Valleys, is the name often given to the valley of the River Tawe area in southern Wales, United
Swansea Canal culvert through large metal grids. There was a short tramway from below the lock to Ynys-penllwch Graig-ola Colliery. Mond Lock was next, with the B4603 crossing the tail of the lock. Below the bridge is the Mond Nickel Works, set up in 1900 after the chemist Dr Ludwig Mond discovered a process for producing pure nickel. Nickel ore was imported from Canada, and the site was chosen because there were supplies of anthracite coal, water, transport links to Swansea, and an available labour force. The canal crosses the Lower Clydach River on an aqueduct, which discharges water into the river,