Area: 140 km 

Cardiff is the capital of Wales and its largest city. Located on the south coast of Wales it is administered as a unitary authority. It was a small town until the early nineteenth century and came to prominence following the arrival of industry in the region and the use of Cardiff as a major port for the transport of coal. Cardiff was made a city in 1905 and proclaimed capital of Wales in 1955. According to 2005 population estimates, the population of Cardiff is around 319,700, making it the 16th largest settlement in the United Kingdom.

Cardiff is bordered to the west by the fertile plains of the Vale of Glamorgan, to the east by the city of Newport, to the north by the South Wales Valleys and to the south by the Bristol Channel. The River Taff winds through the centre of the city and together with the River Ely flows into the freshwater lake of Cardiff Bay. A third river, the Rhymney flows through the east of the city entering directly into the Bristol Channel. A fourth river, the Lleucu, has been culverted.

Cardiff is built on reclaimed marshland on a bed of Triassic stones; this reclaimed marshland stretches from Chepstow to the Ely estuary, which is the natural boundary of Cardiff and the Vale of Glamorgan. Triassic landscapes are usually shallow and low-lying which accounts and explains Cardiff's flatness. The classic Triassic marl, sand and conglomorate rocks are used predominately throughout Cardiff as building materials. For some bizarre reason, many of these Triassic rocks have a purple complexion, especially the coastal marl found near Penarth. One of the Triassic rocks used in Cardiff is "Radyr Stone", a free-stone which as it name suggests is quarried in the Radyr district. Cardiff has also imported some materials for buildings: Devonian sandstones (the Old Red Sandstone) from the Brecon Beacons has been used. Most famously, the superbly elegant buildings of Cathays Park, arguably Britain's finest civic centre buildings are built of Portland stone which was imported from Dorset. A widely used building stone in Cardiff are the surreal yellow-grey Lias limestone rocks of the Vale of Glamorgan, including the very rare "Sutton Stone", a conglomerate of lias limestone and carboniferous limestone that is, apart from Radyr Stone, the only free-stone in South-East Wales (freestones can be cut to a perfectly smooth surface). The yellow-ish complexion of the lias limestone used mainly in the city centre give Cardiff an unusually sunny, light and breezy complexion for a city in the U.K..

Cardiff is situated near to the Glamorgan Heritage Coast, stretching westward from Penarth and Barry (which are commuter towns of Cardiff), with its striped yellow-blue Jurassic "lias" limestone/carboniferous limestone cliffs that thrust outwards towards the Bristol Channel. The Glamorgan coast is the only part of the Celtic Sea that has exposed Jurassic (blue lias) geology. This west facing stretch of coast, which takes the brunt of brutal Atlantic westerlies and has reefs, sandbanks and serrated cliffs aplenty (like Cornwall) was a ship graveyard during the age of sail; ships sailing upto Cardiff during the industrial era often never made it as far as Cardiff as most were wrecked around this hostile coastline during brutal west/south-westerly gales. Consequently, just like its Celtic cousin in Cornwall, smuggling, deliberate shipwrecking and attacks on ships became a way of life for many people living in the small coastal villages of the Vale.

Cardiff is linked to the West Somerset/North Devon seaside resorts (such as Minehead, Ilfracombe and Lundy Island) via the paddle steamers Waverley and Balmoral which sail from Penarth pier, as they have done for over 150 years. Sailing across the Bristol Channel to North Devon is a much a part of Cardiffian life as a pint of Brains and watching rugby. In fact, Devon's tourist trade began in the 19th century when the paddle steamers spent weekends crusing the Bristol Channel taking the expanding population of Cardiff to places such as Lynmouth, Ilfracombe, Bideford and Clovelly.

Cardiff is a relatively flat city and its geographic features were influential in its development as one of the world's largest coal ports. Most notably this included its proximity and easy access to the coal fields of the South Wales Valleys. Cardiff has a relatively dry climate compared to most of Wales[1] , with an average rainfall of 1,065 mm. It is also a relatively mild city,[2] with an average January temperature of 4.5 C and an average July temperature of 16 C