The driver is standing beside the locomotive, which sighs gently. Steam pothers from a brass pipe. “We’ll put you in the first carriage,” he tells us. “Then you can get down at Coed y Bleiddiau.”

We head into a fine saloon car, its seats deeply cushioned and buttoned, everything polished and painted in smart livery. My mother (84) perks up. “Our first holidays were always by train.”

The buffet car attendant takes her order for tea. This is a world of travel that she recognises. “Your grandfather was a railwayman,” she reminds me. “And before that, they were all engine drivers. And before that, stagecoach drivers.”

When I was first told this as a boy, I imagined Wells Fargo, guns blazing across Texas. Disappointingly, it proved to be the stage from Abbots Bromley to Birmingham, but the allure of the driver, the professional traveller was established, adding to the magic of the steam train.

I am not the only one who feels this deep atavistic attachment. There are grown men in our carriage who have come from East Yorkshire and Cornwall for this journey. People work for free on this railway, the Ffestiniog. Their pleasure is infectious. People talk. People look out of the window. It’s a happy railway.

I sink into a plush seat. Take me back in time to an age before computers, cars and stress. The whistle blows. I’m ready.

Facebook Twitter Pinterest The author’s mother enjoys the view as the train crosses the Glaslyn Estuary near Porthmadog. Photograph: Kevin Rushby/The Guardian

Ffestiniog is the right place for such follies. It is run by the oldest railway company still in existence – founded in 1832 – and some of the oldest working locomotives in existence haul passengers along its 13 miles of Snowdonia. When the death of Blaenau’s slate quarries made it redundant in 1946, an army of volunteers, donors and rail enthusiasts seized their chance. The Ffestiniog now connects with national rail services (at Blaenau) and a second steam service, the Welsh Highland, which can extend the journey all the way to Caernarfon (from Porthmadog). There is nowhere better to roll back time and enjoy some steam-powered pleasure. And now, with the refurbishment of Coed y Bleiddiau cottage by the Landmark Trust, it is possible – actually essential – to take the train on holiday. The road doesn’t get close. Nor does television or wifi.

Thirty minutes later the driver brings the train, hissing and steaming, to a halt. Our cottage has its own request stop out in the oak forested hillside above the Vale of Ffestiniog, between Tan y Bwlch and Dduallt. The woods are wreathed in mist, lending it an air of mystery. The sense of time dislocation only increases as we step inside the cottage, a stone bungalow next to the track: everything appears locked in another era, one of evenings spent in armchairs by the fire listening to the wireless. “That’s how we all lived,” says Mother approvingly.

Facebook Twitter Pinterest The cottage has connections to a well known composer and a famous cold war spy

The house was built in 1863 for the railway manager, but by the 1920s it had become a holiday cottage. The composer Granville Bantock rented it for many years then passed it to Harry St John Philby, the highly eccentric father of a boy named Kim, later Britain’s most notorious traitor. There is an excellent shelf of books covering this and many other subjects.

Having fallen derelict, the cottage opened in April after a year-long restoration by the Landmark Trust who saw the potential in such a historic building in a magnificently isolated location. Rotten timbers and peeling paint were removed, but original features such as the beautifully worn slate floors and kitchen range were kept. “That’s how everyone cooked,” says my mother, a little disappointed that it is only for show. We have to use the modern electric kettle and cooker. At least the plates are all on smartly painted display shelves, just like the old days, and there’s a fine brass bedstead in one of the bedrooms. “I like it,” says Mother. The Landmark Trust doesn’t know, but they have just survived their severest test.

Facebook Twitter Pinterest The restoration kept as many original features as possible. Photograph: John MIller/Landmark Trust

Next afternoon I hail the train, which in summer passes by every hour, and head back up to Blaenau, three stops away. My plan is to walk home, after buying cocoa. (“Don’t forget the cocoa!” No, Mother, I won’t.) Supplies in the old days were thrown off passing trains, but now a slip of memory means a big journey.

Blaenau, I have to say, looks in need of its own restoration society, preferably staffed with passionate volunteers bearing paintbrushes. But it is railways, not towns, that gather such zeal. There are around 20 steam railways operating in Wales, arguably making it the world’s leading steam destination. Each one makes useful connections for anyone planning a day’s walk. The Fairbourne, for example, links passengers to the Barmouth ferry, and there’s the Rheidol, which climbs from Aberystwyth to the stunning Devil’s Bridge. My own plan is to use the railway to save me from a circular hike.

Facebook Twitter Pinterest The river Goedal in the woods below Blaenau. Photograph: Kevin Rushby/The Guardian

I leave Blaenau and head south down the Goedol river, eventually entering the woods below and discovering a marvellous set of cascades that lead on through three national nature reserves. These oak forests are preserved remnants of ancient woodlands, home to myriad rare creatures. There are 286 species of small moth alone. Towards evening I sit on a green mossy rock mid-stream and let the waters rush around me. Time slows. The light fades. Creatures stir.

I’m hoping for bats as these woods are home to the greater horseshoe, a rarity, but it is too cold for them. Once upon a time, I might have heard wolves. This was their last haunt in Wales before extinction in medieval times. Not everything has been saved, not yet. Soft veils of mist touch my face. I head back in twilight, restored.

• The trip was provided by The Landmark Trust. A four-night stay at Coed y Bleiddiau, which sleeps four, starts at £356. The Ffestiniog Railway operates between April and October. An all-day adult rover ticket is £25 and also entitles one under 16 to go free. A single from Porthmadog to Blaenau is £16.80