Helen Skelton slipped into a leopard print bikini for a spot of wild swimming while Dan Walker admitted that 'he might be in love' on Tuesday.  

The old friends are travelling up the 'Backbone of Britain', on their very own Pennine Adventure, for the new Channel 5 show, Helen And Dan's Pennine Adventure. 

The series will see them explore the epic mountain range on their doorstep, travelling from Dan's home in Sheffield up to Helen's home in Cumbria, having some great adventures along the way. 

Helen, 40, and Dan, 46, explored one of the Yorkshire Dale's deepest caves before they made their way to Pendragon Castle for a picnic. 

Enjoying the grounds of the castle, they took a plunge in to the freezing cold river, with Helen exclaiming: 'It's freezing!'

'I have to hand it to Helen, I think there might be something to this wild swimming lark,' Dan admitted. 

Later on in the show, viewers saw the pair go horse riding, where Dan jokingly added that he should carry on the show with his horse Roger, for 'Dan and Roger's Pennine Adventure.'

Setting off on their travels again the duo headed to Malham where they stopped off at The Tan Hill Inn - the highest pub by altitude in Britain.

'I didn't think I'd feel this way about Roger. I might actually be in love with him,' Dan admitted to Helen while they enjoyed dinner.

Throwing away the guidebooks, they discover the 'real' Pennines, as they ask the people who call the area home, for their suggestions of where to visit. 

The first episode, which aired two weeks ago, is already a hit with fans - with one writing: 'Loved the first episode of Pennine Adventure. Beautiful views and so enjoyed the banter between the two of you. Great show!' 

Putting themselves outside their comfort zones the series will also seem them try some adventure sports, learn about the rich history of the places they visit and meet the proud men and women who safeguard this breath-taking landscape.

The adventure begins in The Peak District, Britain’s first national park. From the stunning Bamford Edge, Dan and Helen survey The Pennine Way, stretching all the way to Scotland, and discuss The Kinder Trespass, in which defiant protesters won the right to roam.

In the village of Edale, the official gateway to The Pennines, Dan and Helen shear a sheep with third-generation farmer James Metcalfe. 

While setting up camp one night,  Dan gets the outdoor cooker going, while Helen strips down to her bikini to jump in the hot tub.

'I think this is what Pennine life is all about,' Dan says.

'I'm cooking tea, and Helen is in the hot tub'.

Showing the natural chemistry with the pair, Helen ask Dan to 'keep it down'  and 'not make hers too burned' - with Dan quipping back at her to 'shut up'.