I grew up with sap in my veins. We would regularly go for walks in woods, on moors and by rivers in the Yorkshire Dales where I was brought up, and my love of the outdoors has always been with me.

When I was a kid my parents took me on lots of British holidays everywhere from Bispham (the select end of Blackpool) to the Lake District or the north coast of Scotland so I've been a fan of Britain and known its infinite variety from a very young age.

I've not forgotten Britain as I've got older and I regularly spend holidays here. I love the Isle of Wight: I've got a flat and a boat there and regularly pootle around the Solent - that's my big switch-off - and we pop down to Penwith in Cornwall once a year too.

There were places I'd never been, though, such as the Norfolk Broads and the programme (British Isles: A Natural History ) allowed me to explore more of Britain. I was amazed by climbing the Munros in Scotland. I'd looked at them from down below before but to actually look across at Ben Nevis from Aonach Mor on a clear spring day when they're covered in snow and there are blue skies is just astonishing.

The series celebrates Britain's diversity and I think it does that well. People end up knowing their own neck of the woods and a particular spot they love, but I don't think any of us really appreciate the amazing diversity of landscapes. This series should certainly make people sit up and think, 'Good Lord, I didn't know we had that.'

I visited 65 counties over two years to make the series. I was learning the background to all these places we were visiting and the reasons why they looked the way they do.

It wasn't all landscape though, there were also some wildlife encounters. We saw swallowtail butterflies in Norfolk and grey seals around the Isle of May in the Firth of Forth and red squirrels at Formby in Lancashire. You can get in among gannets on Bass Rock - thousands of the blighters. They don't run away because they haven't learnt fear.

It's not just about getting people looking at their own islands on the screen, but for them to get off their bums and walk and see it first hand. We've included several guided walks with the series built on places we visit in the programmes but also incorporating a lot of local knowledge. All you'll need is a stout pair of walking shoes rather than a passport and an airline ticket.

I discovered parts of Britain that I want to revisit, too. Being a boater I want to pootle on the Broads a bit more now that I've discovered them and I loved going up to Lewis and Harris in the Hebrides. The Isles of Scilly with white sand beaches and blue sky are just fantastic, as are the gardens of Tresco.

I travelled by plane, train, helicopter and jet fighter - that's a very good way to travel, but you do run the risk of being sick. Helicopter travel for me is the best way to see the British Isles, though, because you're at a relatively low level so you realise just how beautiful a place it is. I like train travel too - provided it's clean and running on time - because the network has grown into the countryside now and some of the runs are fabulous. The run from Fort William to the coast in Scotland is incredible.

You can't beat the diversity of Britain. You can go from the snow-covered mountains around Ben Nevis to the Isles of Scilly - just a few hundred miles apart. They are fantastic spots.

· British Isles: A Natural History starts on Wednesday 29 September at 9pm on BBC One. A book to accompany the series is published on 4 October by BBC Books. To order a copy of British Isles: A Natural History by Alan Titchmarsh for £18.99 with free UK p&p, call the Observer Book Service on 0870 836 0885 (observer.co.uk/bookshop). For further information on tailored walks in your area visit www.bbc.co.uk/nature