Walking through the door is like opening the window on an advent calendar: the walls are painted a vivid raspberry, and wintry draughts are kept at bay by thick red curtains across stone doorways.
It includes a new convention centre and indoor arena with four potential sites: the current County Hall site in Cardiff Bay, the Red Dragon cinema complex nearby, the site of the Brains brewery and Callaghan Square, which are both situated close to Cardiff's central railway station.