Travelers are voting Whitchurch Hospital, Millennium Stadium and The Folly Tower as the best of 7 key buildings in Cardiff. There is 1 key building in Swansea a city just 34 km from Cardiff. The most popular of these is BT Tower in Swansea. You can find 332 Key Building in the country of United Kingdom and Derwent Valley Mills is our members favorite Key Building in all of United Kingdom. Want more? Check out our map of key buildings in Cardiff.