Cardiff, Wales I can't really say that I have visited Cardiff, but I have been there. considering I took a 12 hour bus ride from London to Cardiff, only to be in Cardiff for less than 24 hours... Nevertheless
Castle Arcade, Cardiff, Wales. The Castle Arcade is a shopping arcade in Cardiff, South Wales. Started in 1887, it runs south from opposite Cardiff Castle, and then turns east to exit on the High Street, north of St Mary's Street, in the Castle Quarter.
Roald Dahl Plass, Cardiff, Wales | The "Doctor Who" Superfan's Guide To Britain. - "Roald Dahl Plass is the site of a spatial-temporal rift in Cardiff, appears several times throughout the series. It’s also the locations of Torchwood Three headquarters in the spin-off series."
Morgan Arcade, Cardiff, South Wales, UK - "Up until the 1790s there were only 25 retail shops in Cardiff, most of them market stalls. The Royal Arcade opened in 1858 and that significantly increased the number of shops in Cardiff." - Things to do in Cardiff in Winter