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 Bay Barrage climbers being used to access the barrage's more difficult sections. It was Varini's first work in Wales and the UK and took a year to plan. The bronze mermaid which stands on the roundabout at the Penarth end of the barrage was designed by Cardiff graphics artist Roger Fickling and comprised the official logo of the Cardiff Bay Development Corporation. It was installed on Vale of Glamorgan land because of tensions between the CBDC and Cardiff Council (see above). There are now three yachting marinas associated with the barrage: The barrage was used as a special stage during the 2010