A five-day hurricane which saw Tiger Woods concede defeat in the Ryder Cup petered out as we hit the tarmac at Dublin Airport. The good omens continued on the drive into town, when I spotted a bedraggled figure at the bus-stop. 'Stop the car!', I yelled, for it was Donal Lunny, musician and old friend, whom I had interviewed from the ABC studios in Sydney only the week before for a forthcoming series on Irish traditional music.* Donal had composed the opening ceremony for Ireland's first hosting of the Ryder Cup in September- a spectacle that enthused the nation, but sadly for Donal, did not extend to a cab voucher. With five of us in the car, we couldn't give him a lift either. I was home for three weeks with my sons to recce an Ireland I'd left twenty-one years before. The sight of the co-founder of Planxty patiently awaiting the 16A in Dorset St made the Celtic Tiger seem comfortingly absent, and my Dublin still familiar.

Just as most Parisians have famously never climbed the Eiffel Tower, as a Dubliner I managed to NOT do what tourists treasure - hear the Viking history, see the Book of Kells, visit the National Museum. The first pleasing thing about the Museum is that admission is free. You can wander in for twenty minutes just to get out of the rain, or lose yourself there for half a day. It's hard to tire of those exquisitely fine sheets of gold that the ancient Irish fashioned into torcs, armlets and enormous pendular earrings between three and four thousand years ago. From the early Christian era there's the wondrous Tara Brooch (8thC), the ornate Ardagh and Derrynaflan Chalices and the beautiful Cross of Cong (12thC). Here, an Ogham stone, etched with the linear alphabet of 1500 years ago; there, a sheela-na-gig, the carving clearly depicting fingers spreading female genitalia. 'If we did that today we'd be locked up', an American woman beside me observes with a grin. A dug-out canoe made of oak, fifteen metres long, takes up an entire wall. From 2,500 BC, it still looks seaworthy. It was naturally preserved in a peat bog, as were my favourite exhibits, the Bog Men. Clonycavan Man, found only in February 2003, dates from around 300 BC and still has his hair, while Oldcroghan Man, discovered May 2003, has fingernails that would do a drag queen proud.

Warming to my tourist persona, I board the Hop On Hop Off bus. The driver, a Dub, mixes anecdote and history and I realise how much I didn't know. Jonathan Swift, author of Gulliver's Travels and Dean of St Patrick's Cathedral, was known for his savage satires, but esteemed by his parishioners for his compassion towards the poor. Under Dublin Castle runs the Poddle river, backing up in the dungeons to form the black pool, 'Dubh Linn', that gives the city its name. My son Conor, 11, is horrified to hear that James Connolly was nursed back to health here after being captured in 1916 - only so that he could be executed at Kilmainham. At the Jail, an articulate young guide completes the story: he still couldn't stand when the time came, so they strapped him to a chair in the Stonebreakers' Yard and shot him. By the time Conor hears how Anne Devlin, Robert Emmet's housekeeper, was half-hanged twice to make her provide information ( she didn't), he is revising his opinion of the English. And we haven't even mentioned the Famine.

I sample the Dublin Literary Pub Crawl. Excerpts from Behan and Beckett and a hilarious story about Oscar Wilde outdrinking (and outsmarting) homophobic miners in Kentucky. The new Yeats Exhibition at the National Library mesmerises: a voice intones the poem as images of Wild Swans at Coole float by, rare archival footage of Maud Gonne shows a woman less beautiful than I'd imagined, handwritten drafts of those poems learnt by rote at school and thank God for that, for I remember them still.

Sheepishly, I venture to the Guinness Storehouse. A trifle hokey - but on the fifth floor, the small eighteenth century harp once played by the great Denis Hempson, whose life spanned three centuries. The last to use long fingernails to pluck the strings, he was born in 1694 and died in 1807. This dark brown carved instrument, with its serpent-head top, is the insignia for the famous Guinness harp.

We head West, the landscape as beguiling as ever, despite the scarring of ostentatious villas, housing sprawl and wind farms. On the Burren, like Wandering Aengus we pluck hazelnuts from the trees on our way to the ninth-century Cahercomaune Fort, and eat thick seafood chowder at silvery Ballyvaughan. Out past Galway to the russet beauty of Maam Cross and on to Doolough Pass. Maybe it was Willie Clancy piping away, but even before we reached the black choppy waters of the lake a sense of foreboding grew. The sun (we had unseasonal blue skies most of the time) disappeared and the mountains loomed large and forbidding. 'This place is mean', said Conor, even before we got out of the car. It was here that a hundred or so women and children from Connemara perished in the Great Famine. Ragged and starving, they had somehow made it over the mountains to the big house, Delphi Lodge, looking for food. They were turned away and died on the road. In 1991 a marvellously diverse group of walkers commemorated their journey, including striking department store workers, the actor Gabriel Byrne and a native American from Oklahoma, whose dispossessed Choctaw tribe had sent a donation to the locals last century when they heard of the tragedy.

A kilometre on, I round a bend and spot a sign:'Delphi Lodge: Wild Salmon for sale'. The house is beautiful, classic Georgian, the grounds splendidly autumnal. No inkling here of the dark past. No answer at the pillared front door either, but as we turn to leave, a red van drives up. 'Murderer!', I think irrationally, then enquire pleasantly if I can buy some salmon. Guilt enhances its exquisite flavour.

In Sligo, we search for the Fairy Glen, its location divulged only to those who will appreciate its mystic grandeur: walk back 100 metres from X until you see a white stone well. Opposite, hidden under creeper, is a wrought-iron gate. we push open the gate, walk along a narrow muddy path. Small blue stalactites have formed from the constant drip drip down the mossy wall, but otherwise it is frankly disappointing. The path broadens into a thicket - what seems a dead end. But Declan, 14, pushes through the sticky black mud to one corner and shouts out in surprise. We follow, gingerly. Behind a creeper of briars and brambles, the track opens into a massive clearing, fifty metres long and about fifteen metres wide, enclosed by high stone cliffs. A few huge trees tower over the leafy undergrowth, one a dead stump, rising like a totem pole, others fallen diagonally across the gorge. Except for the occasional wood pigeon it is quiet - eerily so. The antiquity is palpable. I feel it as I have felt it at ancient, isolated rock formations in Australia. But there, it was screaming at me to leave. Here, I feel a wary belonging.

What rituals went on between these fern-covered escarpments? A troop of men could hide here, to surprise the enemy. An entire community could shelter, as the Vietnamese did in their tunnels at Cu Chi. There are signs of recent use - a burnt out fire with its circle of stones, an upturned stump to sit on. Conor is fretful, Declan exultant. 'It's special. You should feel awe and respect for it, not be frightened.' He wants to go on; Conor refuses. I compromise, wait with Conor while his brother sallies forth, thrilling to the power of the place. Ten minutes, I say. As he pushes into the undergrowth, I quell a sudden terror that he will never be seen again - vanish, like the girls in Picnic At Hanging Rock. We wait. Conor thinks he sees a bat, but it's too far up to tell. I am surprised my mobile phone still has reception. I turn it off, to avoid a sacrilegious ring. Although it's light in the glade, my photos look impenetrably dark; the Fairy Glen won't yield its secrets. A whoop, and Declan's back. The path gives way to another gorge, he says; he didn't have time to explore it to the end. He is joyful, exuberant.

That afternoon we head to Carrowmore, the oldest megalithic burial ground in Europe. Some forty graves and passage tombs are scattered across fields, along with three circles of standing stones, to the blithe unconcern of grazing cows. As we buy our map, Declan asks their age in relation to Stonehenge. 'The oldest go back seven thousand years', says a round-faced man behind the counter - 'two thousand more than Stonehenge'. Earlier, we had climbed Knocknarea and seen the cairn supposed to mark the burial place of the legendary Queen Maeve, who went to war with Ulster to get hold of the noble Brown Bull. 'Lots of the stones were quartz', says Conor. 'Why is that?' The man, whose name is Padhraig, explains that quartz was significant, called grian-cloch, or sun-stone, often placed on important graves. To this day it is considered unlucky to bring quartz into a house.

Pleased with the lads' interest, Padhraig volunteers himself for a guided tour. It is a revelation. As we pick our way through the cow pats towards one passage tomb or another, Padhraig lightly covers seven thousand years of human civilisation - not just in Ireland, but linking the advent of agriculture, the origins of domesticated beasts like the cow, the spoils and fall-out of war and hunting and even romance. Queen Maeve had many lovers, he tells us, but one of them fell for her sister. A jealous Maeve killed her sister, who left behind a baby boy. When the boy got old enough, he made a slingshot, took a piece of 'very mature Cheddar', and took out Queen Maeve. 'Possibly the first cheese murder in history', Padhraig wryly observes. We stopped by a replica of her tomb. It was late afternoon, the sun still shining. Carrowmore was ringed by far-off mountains and one by one, Padhraig picked them into focus. 'That one there, that's Cnoc na Si. the sun rises there in winter and on the shortest day, it will set behind that peak. The tombs it lights during its journey form a Y. In summer, they start there, form an X.' I felt like a dyslexic suddenly able to read; the landscape now made perfect sense.

I am still reeling from the emotional impact of that trip. Back in Sydney, Conor has nominated Irish History for his latest school project, and apart from dark mutterings about The Brits, is agog with new knowledge. Declan has discovered his personal Narnia in the Fairy Glen, is already making plans to step back through the wardrobe next trip. The years force-feeding them Fionn MacCool, Cuchulainn, Brian Boru and the Famine never made a dent - but somehow this short intense immersion has clicked. They finally get it, this thing called Irish culture, and have begun to claim it as their own.