Iolo Williams delves into the archives to see the fantastic wildlife that he has filmed in Wales during the past twenty-five years. He also explores the changes he has seen in Welsh wildlife in that time. In this episode, he goes back ten years to eight hundred ravens roosting in Newborough Forest, Anglesey and their extraordinary calls. He recalls a visit to Grassholme Island off the coast of Pembrokeshire in 1996 to see a colony of over a hundred thousand gannets. Also in the episode, the wildlife of slate quarries, the breath-taking underground landscape of a mine in Blaenau Ffestiniog, and a fantastic reef formed on a slate-boat wreck off the coast at Nefyn. Other gems include the parachuting displays of skylarks and rock pipits, and a couple of boat trips with fishermen in Cardigan Bay and the Dee Estuary.