Scotland has a lost archaeological history - the ruins of thousands of townships and buildings which have never been recorded on any map, yet which tell the tale of life in a period of dramatic change. Mark Stephen follows attempts to uncover those stories before the buildings fade from the landscape. On the island of Mull, he meets two ladies who stumbled across a lost chapel. As he joins the specialist team surveying the site, he learns that not a single written record of it exists - but that it's probably over a thousand years old. Producer Monise Durrani.