Cardiff is the capital city of Wales and a county. Officially known as the City and County of Cardiff, it is the United Kingdom's eleventh-largest city and the main commercial centre of Wales. Cardiff is the base for the Senedd, most national cultural institutions and the Welsh media. At the 2011 census, the unitary authority area population was estimated to be 346,090, and the wider urban area 479,000. In 2011, Cardiff was sixth in the world in the National Geographic magazine's list of alternative tourist destinations. Cardiff is the most popular visitor destination in Wales with 21.3 million visitors in 2017.