Cardiff in 3 days: Cardiff Castle (the Victorian Gothic fantasy of the 3rd Marquess of Bute — richest man in the world in the 1860s — designed by William Burges: the Arab Room, the Clock Tower Summer Smoking Room), the Principality Stadium (74,500-seat retractable-roof stadium in the city center — the most electrifying rugby atmosphere in Europe), Cardiff Bay (the former coal docks of Tiger Bay — birthplace of Shirley Bassey — now housing the Senedd, Wales Millennium Centre and the Pierhead Building), Castell Coch (the 1875–1891 Gothic Revival fantasy castle in the Taff Valley woodland) and Caerphilly Castle (the second-largest castle in Britain, leaning tower, 30-acre moat).