In the first episode, Ifor explores why ruins are among the best-preserved and most-loved holy sites in Britain. He visits the famous ruins of St Andrews Cathedral, the mystical atmosphere of Wales's best-preserved Roman site, the battered remains of Coventry's iconic cathedral and the Gothic majesty of North Yorkshire's Whitby Abbey - the inspiration behind Bram Stoker's Dracula. Along the way, he asks why we're drawn to holy ruins long after their religious use is over. Is it just nostalgia or something much deeper that fuels our obsession and enduring fascination with the decaying grandeur of a ruin?