Seaside Haunts: Brittas Bay: It was the perfect destination as a child, but then Brittas Bay lost its charm for a teenage Louise East. What does she think as an adult?

A few years ago the property pages featured a well-placed mobile home in Brittas Bay with an asking price of nearly £60,000. The nation gasped. Here was proof, if proof were needed, that the Irish had finally gone mad. For that money - the equivalent of €76,000 - you could buy a three-bed semi in Arklow or, indeed, a 14-bed villa in Spain with tennis court, maid service and solid gold infinity pool, and all for the price of a hulking great caravan surrounded by other happy Co Wicklow campers. No doubt about it, the buyers must have been a few tents short of a scout jamboree. Yet part of me understood this particular form of insanity.

Growing up on the Dublin-Wicklow border, we regarded Brittas Bay as our El Dorado. Just before national school broke up for the summer our whole school would climb on a coach, big boys down the back, volunteer mothers at the front, the rest of us stuffed in the middle, jiggling with excitement. For weeks the name had been repeated over and over, as whispery and sibilant as the waves. Brittas Bay, where the sand was golden, like in our picture-books, and the sand dunes were as toppling and steep as a bank of snow. Brittas Bay, where the water was the colour of a raspberry Mr Freeze. Brittas Bay, where the sun always showed up, because who wouldn't want a trip to Brittas Bay? It nearly always lived up to expectation, although my memories definitely have a greyish, dampish cast.

We played rounders and ran hastily organised races, the sand scudding up in chunks from our bare feet. When the tide turned we made sandcastles with messy, intricate moats that always collapsed before they quite filled up. Lunch was sausages cooked on a concrete barbecue and orange squash that made your teeth squeak. What I remember most, though, is the sheer mystery of those sand dunes, bigger than the pyramids and such a delightfully unnecessary shape. Why did they not slide into the sea? How could you ever climb to the top when every step sent you sliding towards the beach? The best technique was a kind of bestial scramble, hands and feet dug in like crampons, bottom in the air, moving as quick as you could to defeat the shifting sands.

Attaining the very top was impossible, but you could sometimes make one of the valleys between the high peaks. At once the sound of races and burnt fingers died away and the crying of gulls and a roaring peace descended. Fringed with marram grass as delicate as an eyelash, the dunes released a faint warmth, and it seemed possible that a girl could live here, all by herself, for ever.

During the long silky stretch of the summer holidays my sister and I lobbied for repeat visits to Brittas Bay. It was always a risk. In the era before the bypass the traffic could stretch for miles, and the glorious sunny morning you set off in might become a rainy afternoon. Midweek the beach seemed oddly quiet, the amount of sand on display overwhelming.

We had to hare around and screech a lot, just the two of us, to fill the gaps. After the sandwiches had been eaten, and the chocolate licked off a United bar, we felt more at home. We would take it in turns to lie in a shallow trough and be covered with sand, shaped into a mermaid's tail. No matter how warm the day or how dry the sand, always you became aware of a tickling, creeping damp from below, like pee only colder. The minute my sash of seashells and seaweed was in place I shot upright, jigging and wriggling to get rid of the shivery feeling that I might be dead.

It was only when I hit my teens that I realised not everybody left Brittas Bay at the end of the day. For the first time I met people who practically lived there during the summer, and they talked of a different world. If you owned a place in Brittas Bay you got on your bike at nine in the morning and would be hard pressed to get back to the mobile before sundown. Even an eight-year-old had a packed schedule of tennis, pitch and putt and games you only understood if you had a mobile home in Brittas Bay.

Dads were lucky - they got a few days' respite from Monday to Friday - but come the weekend they were expected to drive down from Dublin and join the mums for card games, drinks in Jack Whites, rounds of golf, barbecues (especially the barbecues), swimming and gossip. At this Brittas, of boys, bikes and bonfires, friends had their first snog and drank cider for the first time, often both in the same night. With the unshakeable certainty of the disgruntled teen I knew my life would be different, and better-different at that, if instead of camping in France we had a place in Brittas.

Later I got the chance to see what I had missed. A college friend invited a group of us down to her family's mobile home in Ballinacarrig Park one still and sunny summer day. It was everything I could have wished for. We played football on the coarse grass, and for the first time in my life, and probably the last, I sent two whackingly perfect shots between the pampas-grass goalposts. We cooked chicken on the barbecue to the sound of Gay Byrne leaking through the windows of the neighbouring mobile home. Later we wedged ourselves around the Formica table in the kitchenette and played poker late into the night.

But it was too late; everything I had once coveted seemed deeply suburban and tame. The cosiness of it, which I had once longed for, now felt suffocating. Foreign climes, that was the thing: rainforest and cicadas and winding roads leading to the sierra. If there were to be beaches I wanted them wild, remote and unspoilt, rocky clefts where the sea met the shore and anything might happen.

That summer I was listening to Joni Mitchell, who sang of meeting a redneck on a Grecian isle and going to a party down a red-dirt road, and I decided there was no reason why I shouldn't join her. Air fares were getting cheaper and backpacks bigger; why on earth would you waste your time hanging around in Brittas Bay?

What I simply didn't hear was that Mitchell's California was a hymn to her own home: "I might have stayed on with him there / But my heart cried out for you, California."

The one thing travel is almost sure to give you is a new, richer perspective on your country, and before long I realised that Ireland has a unique and beautiful coastline. Over the past few years I've swum in Clew Bay, in Co Mayo, Dog's Bay, in Co Galway, the Forty Foot, in Co Dublin, and Ballycotton, in Co Cork, with all the noisy enthusiasm of the recent convert (and the temporarily frostbitten).

But I hadn't been back to Brittas until a friend threw a party at his family's holiday home in north Co Wexford late last summer. Driving down the N11 as the sun started to fade, we saw the sign for Brittas and pulled off on a whim. I was apprehensive, but unlike most places remembered from childhood the road into Brittas hadn't changed much. There are many more mobile homes and holiday bungalows, but a lack of services has kept the place low and sandy rather than high and white.

The dunes seemed smaller; perhaps that was inevitable. Yet the winking marram grass and the clean curve of the peaks silhouetted against the sky lent them a composure even the new wood-and-wire paths and litter bins couldn't take away.

The beach, though, was longer and wider than ever, although closer to the colour of a donkey than the golden glitter of memory. We all stripped off and ran in for a swim.

Later that night I swam again, ducking away from the singing and the bonfire on the beach to scull out into the shadowy dark water. As I raised my arm in a lazy backstroke tiny lights sparked off it, like underwater fireworks or the sequins shooting from a mirror ball. Phosphorescence, a fleeting and magical natural phenomenon I had never seen in all my foreign travels. Really, I thought, you could do a lot worse than buy a house in Brittas Bay.

In Weekend Review tomorrow: Thomas McCarthy on Dungarvan Bay, Co Waterford