The intrepid TV presenter talks to Abi Jackson about his staycation plans and favourite spots, from Scotland's West Highland Line to Brighton beach.

Simon Reeve has a great trick for getting his 11-year-old son excited about walking up hills with him. He tells him they're massive mountains.

For example, Dartmoor is not too far from where the TV presenter and travel enthusiast lives in Devon - home to High Willhays, "which is the highest mountain in Southern England," says Reeve. "I mean, it's really a very large hill. But if you're trying to get your 11-year-old children up there, that gives them an incentive and an inspiration to get them climbing."

It's perhaps no surprise that days out with Reeve - whose drive for adventure has seen him explore the likes of the Americas, Australia and the Indian Ocean for the BBC, and author books such as Journeys To Impossible Places and Step By Step: My Life In Journeys - involve taking in some fresh air on foot.

"I am a bit of a pain-in-the-bottom father who is always trying to find us a walk to do and strap on those boots," admits Reeve, 49, who has 11-year-old Jake with wife Anya. "And actually, as long as I'm not forcing him to do it too much, he really loves it. As long as we're mixing it up, then I'm reasonably good at encouraging him - or bribing him! - to go for walks."

In fairness, he does mix it up. In fact, Reeve's adventure wish-list this year involves exploring cities and soaking up history too - making use of the UK's rail network.

"We don't live on the biggest island, but we've got some really beautiful sights, incredible cities packed with history and cafes and joy. There are places I want to get back to, places I haven't been," says Reeve. "I haven't been to York since I was a nipper, really, and I'd love to go back there. One of my aims now is to take my lad - I want him to see Britain as well.

"One of the other places I'm keen to go to by train with my son is Lincoln Cathedral, one of the finest buildings on planet Earth - that's on our do-do list.

"When I was a kid, going on the train, on those 'away day' holidays, was a really big deal," he adds. "We didn't go on exotic foreign holidays when I was a kid, I didn't go abroad until I was an adult. So the train was a proper passport to adventure."

This explains his enthusiasm for teaming up on a new rail industry campaign championing UK train travel. Launching on Earth Day (April 22), they're running a competition to find three 'chief environment officers' - CEOs - who will each win £10,000 to explore the UK's train routes and 'uncover the green credentials of some of Britain's best locations'. Applicants need to submit a 60-second video about a recent trip (by midnight on May 1), showcasing why they should win and their passion for sustainability.

A survey accompanying the campaign found almost half (46%) of Brits don't know travelling by train is the most sustainable form of transport, compared with cars and planes. However, opting to go by train, rather than driving for summer vacations, could help people cut their carbon emissions by two-thirds.

"The train, short of walking, is just about as good as you can get in terms of travelling in a greener way," says Reeve, who will also be one of the judges tasked with picking the winners. "The 'CEOs' are going to show us some of the best places in the country that can be reached by train, and hopefully inspire us to follow in their tracks. And we know that a huge proportion of Brits are looking to spend more time in the UK this summer, which is great."

His intrepid career may have taken him to some of the farthest corners of the globe, but as somebody who grew up in London with no holidays abroad - and who left school with just one GCSE, already no stranger to mental health problems - exploring the UK by train has a special place in Reeve's heart.

"One of my absolute favourite train journeys is the West Highland Line in Scotland. That still gives me an absolute tingle," he shares. "Travelling from Glasgow to Oban or Fort William - it is considered by many to be one of the most scenic railway journeys in the world, and I travelled up there quite young, actually. It was quite a difficult time in my life, and it was the journey that really helped transform me from quite a depressed young lad into somebody who saw adventure as a possibility in life. So that's a train journey that helped make me the human being I am today, no less."

Other favourites include the Lake District: "I was filming a series there last year [The Lakes for BBC Two] and I'd go up and down from where I live in Devon on the train. You can walk straight out of Windermere station to one of the hills around the back called Orrest Head, and you get incredible panoramic views of some of the major fells of the Lake District - Old Man of Coniston, Scafell Pike - glorious views."

He still has a soft spot for the beaches of England's south coast too: "Studland is one of my absolute favourites, and I really love Brighton. I love that pilgrimage, if you're a Londoner like I am originally, when the sun gets warm and you book your seat on the train down to Brighton."

"Trains aren't just a means of transport, they give us an adventure on the journey as well. The view out of the window is so interesting for me, I love that big panoramic window, the view it gives you of the landscape and people's back gardens and lives - I'm very nosy.

"If you're on a motorway, you're often just looking at that sort of embankment on either side. Travelling on a train, you are looking down at the countryside you are passing through, and towns and villages and seeing human life as it's lived," he adds. "It's a window into our existence, and into some of our finest, most beautiful regions."

For more information and to enter the competition to become one of the rail industry's 'chief environment officers' by midnight on May 1, visit nationalrail.co.uk/CEO