The Story of Wales: Creating a CGI Roman amphitheatre from ruins
Caerleon, near Newport in south Wales, is one of Wales' best known and loved Roman sites.
In its heyday, this open-air arena would have seated up to 6,000 people and been the scene of gladiatorial games against men and beasts.
Computer graphics from the BBC Wales history series, The Story of Wales, helped to bring that scale and structure to life.
But how do you go about turning shots of stone ruins into a virtual amphitheatre from around AD90?