In this fourth episode, Kate walks a hilly coastline that is home to two of north Wales's most popular tourist destinations — the medieval walled town of Conwy, and the Victorian resort of Llandudno, once dubbed the Queen of Welsh resorts.

In this third episode, Kate walks a rugged and scenic route along Ayrshire's coast, the birthplace of Scotland's National Bard, poet Robert Burns. Less than an hour from Glasgow, this corner of southeast Scotland is rich in history and pristine wilderness.

Kate's starting point for the latest leg is the picturesque village of Alnmouth, once a leading grain port in the 18th century. Today it's known for its colourful houses and a gentle sweep of sandy beach where Kate meets a former GP, Claire, who uses the sand to create temporary large - scale artworks and portraits, which are visible for a few hours only, before the tide swallows them.

The naturalist wanders along the shorelines of Britain. On Holyhead Island in north-west Wales, Kate discovers one of her favourite rare birds and Britain's longest breakwater - a 1.7-mile-long feat of Victorian engineering.