Tom Heap and Margherita Taylor look at the impact of canals on the past, present and future of our countryside.

In the Midlands, Tom is on the UK's longest canal – the Grand Union - discovering the engineering triumphs that helped traverse our rugged landscape and how they could now play their part in a 21st-century green tech revolution.

Meanwhile, Margherita celebrates the 200th anniversary of the Regent's Canal, finding out how this once commercial route now brings a slice of countryside to the city, benefitting both residents and wildlife. Tom also investigates what's going into our public sector meals, wildlife film-maker Jack Perks dons his wetsuit to get up close to some frisky frogs, and we pay our first visit to Brookvale Farm in Northern Ireland, where we will be following the fortunes of a family staking their future on the success of hi-tech farming.

Helen Skelton is in the Nidderdale Area of Outstanding Natural Beauty in North Yorkshire, helping prepare for the return of both animals and visitors to the hills. She joins a team keeping track of adders emerging from hibernation, to find out why numbers are falling. She also joins in with efforts to help save essential woodland and its wildlife, and discovers hidden wonders as she heads into the depths of How Stean Gorge. On his Cotswold farm, Adam Henson is struggling with the unpredictable spring weather. Tom Heap investigates how a rise in pet ownership is fuelling dog thefts and wildlife film-maker Jack Perks celebrates one of our most colourful but overlooked freshwater fish – the grayling.