At Crom Castle in Co Fermanagh your family can live like aristocrats. Bill Tuckey worried his clan might get a little too used to it all...

The last time I crossed the Irish Sea on a family holiday was 30 years ago, on a heaving rustbucket of an overnight ferry, awash with the vomit of a hundred drunken navvies. We went to stay in a tiny rented house on an unmade track, with no hot water or electricity; the only luxury was sampling the tasty local cheese and onion crisps.

At Easter, with three children of my own in tow, things could not have been more different. Our two-hour super-fast crossing from Holyhead to Dublin was all table service, soft-play areas and even softer armchairs. Another two hours along country roads dotted with new bungalows and we found ourselves staring awestruck at our destination: a huge stately home at the end of a long, tree-lined drive.

Crom Castle is an early Victorian, turreted pile set in a 2,000-acre estate in the sleepy, green depths of the border county of Fermanagh, Northern Ireland's own lake district. And it can be yours for the price of a week's high-season self-catering in Newquay. At least the West Wing can. From this year its owner, the Earl of Erne, is offering it for hire to help to pay for the upkeep of his monumental abode. Unless you've got blue-blooded buddies, it is about as close as you could get to a slice of authentic aristocratic living.

As we approached Crom, the children began whispering nervously about cobwebs and ghosts. But their fears quickly vanished once we'd stepped inside. The West Wing's rooms include a great, barrel-vaulted dining room, complete with huge pass-the-salt-please table, and a vast yellow drawing room dominated by ancestral oils. Yet the place still retains the atmosphere of a happy family home.

Slightly outdated checked upholstery, family photos, boating memorabilia and a cosy telly room all seem to urge you to put your feet up and stop worrying about the children breaking that priceless-looking Chinese porcelain in the hall cabinet. Ours loved the sheer scale of the place: running up and down the endless corridors (shouting a lot) and playing hide and seek with the unexpected gusto of characters from an Edwardian children's novel.

There are six enormous, en-suite bedrooms, all with their own endearing decorative theme, including the outrageously floral Rose Room, and the Buff Room, with a fairytale four-poster.

Two or three families could stay here for a week and never feel they were on top of one another, even if it did rain non-stop.

But you really wouldn't want to be stuck inside for too long. The castle lies on the upper part of Lough Erne, a lovely 300-square-mile stretch of water with a shoreline of fjord-like complexity, surrounded by gentle hills and speckled with wooded islands. The castle itself has sweeping lawns, its own deer park and tennis court, and the wider Crom Estate, now managed by the National Trust, is ideal for Swallows and Amazons adventures. Especially since, when you rent Crom, you get the Earl's motorboat too, moored by a Victorian boathouse.

Casting off, we nosed past the wildly romantic Crichton Tower, an island folly built by the family in 1848 when Crom was home to the Lough Erne Yacht Club and the epicentre of Fermanagh high society. Then on, along a shoreline dense with reed swamp and wildfowl to the jagged ruins of the original Crom Castle, built by 17th-century Scottish planters and burnt to the ground by a careless maid with a candle. Beside the old battlements are giant twin yews, thought to be the oldest trees in Ireland.

We took a picnic with us and could have kept on going up the lough all the way to Fermanagh's pretty county town, Enniskillen, a name that for most is linked to a Remembrance Day bombing nearly 20 years ago. Today, it has a thriving high street, lots of good food shops, and an oddly 1970s feel.

On our return to the castle, Noel the charming, Crom-born-and-bred estate manager, had made a fire for us in the drawing room; his mother Violet had cleaned the bedrooms. One could get used to this. In fact, it would be easy to spend a whole week at Crom without venturing beyond the estate gates.

The children passed another happy day with fishing rods and worms, not catching anything on the lough. There are miles of nature trails around the estate, and we could have spent a night in the estate's wildlife hide, trying to spot one of Ireland's rarest mammals, the pine marten.

We did venture out again, driving an hour west, for a blast of Atlantic air on the spectacular beaches of Donegal Bay - until rain came down like an upturned bucket. In high summer Crom's magic will be even stronger. The only snag is once your children get a taste of it, they'll never be happy with anything less again.

A week at Crom Castle (028-6773 8004; costs from £210 per person based on 12 sharing. Stena Line (08705 707070; stena has return ferry crossing from £130 per car plus passengers