Cardiff

Cardiff (Welsh: Caerdydd) is the capital and largest city of Wales and the locstion of a spacetime rift located near Roald Dahl Plass as well as Torchwood 3, located underneath the Plass.

19th century
The Doctor and Rose Tyler encountered Charles Dickens and the Gelth on here on Christmas Day 1879. (DW: The Unquiet Dead)

20th century
During World War II, refugees from the Blitz in London found themselves moved here. (TW: Ghost Machine)

21st century
"Margaret Blaine" had been elected as Lord Mayor of Cardiff following her escape from the destruction of 10 Downing Street. She planned to demolish Cardiff Castle and to erect the Blaidd Drwg (English: Bad Wolf) nuclear power station. She planned on using a tribophysical waveform macrokinetic extrapolator as a pan-dimensional surfboard to escape the solar system after Earth's destruction. (DW: Boom Town)

Circa September 2006, the Doctor, Rose and Jack Harkness, traveled to Cardiff to refuel the Doctor's TARDIS and to meet up with Mickey, the group discovered the plot. The rift partially opened, causing a small earthquke (DW: Boom Town)

By this time, humans living in Cardiff had started to notice and take advantage of the alien presence on their world. Illicit merchants for alien artifacts traded in the town and profited off of alien artifacts such as the "Ghost Machine", which had fallen through the Rift (TW: Ghost Machine). An underground "fight club" where the alien Weevils fought humans also briefly existed for a time. (TW: Combat)

Not knowing exactly how to use it, part of Torchwood 3 team used the Rift Manipulator in order to rescue two of their number out of the past. (TW: Captain Jack Harkness) The resulting disturbance caused disruptions in time to occur all over Earth, as well as in Cardiff. Then persuaded by Bilis Manger, Torchwood 3 used the Rift Manipulator to repair the damage, but also to release Abaddon, a demonic being which killed dozens in the city. (TW: End of Days) Three days later, the Doctor and Martha stopped again at Cardiff to refuel, whereupon Jack Harkness, having just left leader of Torchwood 3, hitched a ride on his ship.