Cardiff in making iron and later steel, brought to the sea by packhorse from Merthyr Tydfil. This was first achieved by the construction of a long canal from Merthyr (510 feet above sea-level) to the Taff Estuary at Cardiff. Eventually the Taff Vale Railway replaced the canal barges and massive marshalling yards sprang up as new docks were developed in Cardiff – all prompted by the soaring worldwide demand for coal from the South Wales valleys. At its peak, Cardiff's port area, known as Tiger Bay, became the busiest port in the world and – for some time – the world's
Cardiff, Maryland Route 165. The town has a post office, several shops, garages, and churches, a fire hall, a general store, and a new supermarket. Cardiff is located in a very slate-rich region, which created the town's early industries. Cardiff was formerly the mining center of Harford County. The mines and quarries have all but shut down now, and the town has become a farming hub. According to geologist Jeri Jones: One cannot talk about the Delta area without including the Cardiff Marble Company, just south of Delta in Cardiff, Maryland. The site was famous for its own mineral resource, "Green Marble"