Holby is a fictional city in the United Kingdom, in which BBC medical dramas Casualty, and Holby City, and police drama HolbyBlue are set. It is based upon the city of Bristol, and is located in the fictional county of Wyvern in the South-West of England, not far from the Welsh border.  While Casualty is filmed in Cardiff, Holby City is filmed in Elstree, Hertfordshire. Both shows are set in the same fictional Holby City Hospital. Holby has an airport called Holby International.