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 Visitor Centre (The Tube) panel of experts as one of the Top 50 Buildings of the 1990s, saying the building had "single-handedly put Cardiff on the architectural map". In 2006 the building's operators, Cardiff Initiative, ceased trading and The Tube closed for several weeks, reopening under the management of Cardiff Council. The Tube was finally dismantled (and put into storage) in Autumn 2010 to make way for a new link road. "I'm surprised it's lasted this long," said original project architect John Lyall. Cardiff Bay Visitor Centre (The Tube) Cardiff Bay Visitor Centre (known informally as 'the Tube') was a piece of modern architecture