Every season of Iolo's River Valleys ever, ranked from best to worst by thousands of votes from fans of the show. The best seasons of Iolo's River Valleys!

Iolo Williams explores the Rheidol valley and looks for elusive pine martens. He’s also treated to views of red kites nesting in a village and explores a remote zinc mine.

The Rheidol Valley

Iolo Williams explores the Dyfi Valley, from Ynyslas dunes and Cors Fochno bog to Ospreys at Cors Dyfi and wild Beavers near Machynlleth.

The Dyfi Valley

Iolo Williams explores four of Wales’s most stunning river valleys from sea to source, uncovering their hidden wonders and remarkable wildlife.

The Best Seasons of Iolo's River Valleys

The Best Seasons of Iolo's River Valleys

Season 1