Cardiff (/ˈkɑːrdɪf/; Welsh: Caerdydd [kairˈdiːð, kaːɨrˈdɨːð] (About this soundlisten)) is a city, principal area and the capital of Wales, officially known as the City and County of Cardiff. It is the United Kingdom's eleventh-largest city. As Wales' chief commercial centre, Cardiff is the base for the Senedd, most national cultural institutions and Welsh media. At the 2011 census, the unitary authority area population was estimated to be 346,090,[4] and the wider urban area 479,000.[5] Cardiff is a significant tourist centre and the most popular visitor destination in Wales with 21.3 million visitors in 2017.[6] In 2011, Cardiff was ranked sixth in the world in National Geographic's alternative tourist destinations.[7]