A day-trip to the Aran Islands summons up images of tourists dressed in plaid who don't see anything unless it's through the lens of a camcorder. And yet . . .

We left a dreary Dublin behind last week as we took the 7.15 a.m. train to Galway. A few hours later, we are standing in the midst of the splendour of the 3,000-year-old Dun Aengus on Inis Mor, the wind in our hair, the cries of the gulls in our ears and the spectacular cliff views below us.

By 9.30 p.m., we are back in Dublin, with sun-kissed skin and tourists' tales, home to deep sleep and jumbled dreams of ancient landscapes, crumbling castles, rapid-fire Gaelic, tiny planes and blindfolded cattle being walked over cliff edges. If the best experiences are supposed to leave you with a taste for more, then this one works.

It works as a day-trip simply because a tiny enterprise headed by two hands-on directors makes sure it works. The logistics of getting maybe 100 passengers on an early train, then connecting them to coaches heading for Aran or the Burren or Connemara, connecting the coaches (in the case of Aran) to the plane at Inverin, connecting the plane to the coach in Aran, and shepherding all 100 all the way back again, safely and happily to Dublin in one day has to be a nightmare. But it's what Railtours Ireland partners, Jim Deegan and David Humphries, with the help of "active retired" rail enthusiasts who act as hosts throughout the tours, do every day.

In just two years of business, they've put 30,000 trippers through their hands. And success isn't just down to the reserved railway carriage, the reassuring host and relentless checking-ahead that come with the package. Each passenger is greeted like a single traveller, not another wad of cash, is chatted to along the way and has the sights pointed out to them.

Deegan and Jack Ahern, our host, radiate a kind of old-fashioned curiosity about their paying guests, in off-season often made up of conference participants and visitors on short Dublin city breaks, and today comprising Mexicans (name of Kelly), French, Scots, Canadians, North Americans, Australians and Finns. There are no tartan trousers among this interesting, mainly professional troupe.

And it says something for the whole operation that they award a round of applause to our hosts at the end of it all - and this despite the revolting state of Heuston Station at 7 a.m. that Monday morning, the time-beaten carriages, the shuffle 'n' stall return train journey (attributed to the rail dispute) that leave us nearly an hour behind schedule, made less bearable by the toilets that refuse to flush.

These blips are of no small moment, because for an encyclopaedic rail enthusiast like Jim Deegan, the train journey - by far the lengthiest segment of the odyssey and therefore with the power to make or mar a daytrip - is more than a monotonous means to an end. It's an integral part of the day-trip experience. So trippers are encouraged to sample the train's Great Irish Breakfast (about £7 and worth it, for quality and cheerfulness of the catering staff) somewhere around Tullamore, where a vast Travellers' halting site and interestingly battered castle excite some comment, followed by a frisson of interest in the bogs, then a crescendo of excitement beginning with the rambling dry-stone walls, reaching its peak upon sight of a seriously sparkling Galway Bay. There is a tactful omission of Mutton Island's most recent history as we cruise into Galway at 10.15 a.m.

Once off the train, there's no hanging around. Jack leads us out of the station at a quick march, despatching us on to coaches for the Burren or Connemara or Inverin. Within minutes, Ian, a Scot, is sitting back happily in our little minibus, expressing some disappointment as we flash through Claddagh ("I thought it would be something different"), but delighted to be out of Dublin which is "too full and prices are very high". On his regular, Dublin-based trips to Ireland, he hires no transport and relies on day trips to see the country. Last year he took four day-tours. By 11 a.m., we're in the "real" west, being eyed up by sheep lining the route of the tarred goat-track to Inverin airport.

In the little two-room terminus, where a couple of Gaelic-speaking fishermen straight from central casting are getting stuck into a few creamy pints, we submit ourselves to a giant (and very public) weighing scales and by 11.15 a.m. are up and away in a teenchy nine-seater plane, cleaving the clear, blue skies at 120 knots.

We hit Aran smoothly at 11.25, and by 11.35 are bowling along in another minibus through Kilronan and up towards Dun Aengus, while our droll driver alerts us to the statistics of Inis Mor: "One doctor, two nurses, three guards and 12 teachers . . . population 900, and 150 cars". Whether the 150 cars include the raft of tour buses skinning the legs off touring cyclists is not clear as we climb the hill and spot the lighthouse that was built too far inland, causing the ships to go "astray", as he puts it.

He drops us at the start of an easy, gradually-ascending 15-minute walk up to Dun Aengus fort, a world away from bustling, crowded Kilronan. It is blessedly free of incongruous fences or admonitions to keep clear of the edge; and it remains, in spite of the millions who've tramped their way around it, magically apart, a breathtaking place where echoes of early Christianity, Cromwellian garrisons, and Land League defiance - which included walking the landlord's blindfolded cattle over the cliff edge - can still be summoned in the elemental landscape.

We climb back down again about 90 minutes later to be picked up by our driver and trundled back to Kilronan the long way round - via ancient sites and churches and unexpectedly vast, uninhabited strips of barren, stone-patterned land. Inis Mor, somewhat to our surprise, despite its buzzing, touristy enclaves, retains its own brand of authenticity.

An hour for a bowl of chowder in Kilronan (and that's long enough, even with a friendly, Irish-speaking waitress encouraging us to use the cupla focail), before our driver returns us to the little airport, the flight to Inverin and back to Galway city for a couple of hours browsing and communing with Padraig O Conaire before the 6.05 p.m. train.

Jack is there, alert and counting, shepherding his flock. We've lost and picked up a few stragglers (a mark of the company's amiable flexibility): a woman who had overnighted spontaneously in Clifden the day before, and a couple who had fallen heavily for the Burren and decided to spend the night.

Dinner and a bottle of wine on the train; travellers' tales with well-travelled, clear-sighted Americans; Jim and Jack pointing out the Curragh and thanking us all for coming. Everyone tired but happy - as we used to write in our school essays.

Daytrippers and proud of it. That's us. Next time we'll bring a camera. And a picnic.

Railtours Ireland runs trips throughout the country, all year round, beginning at £19. The Aran day-trip (excluding food) costs £79. Reservations: 01-8560045.