Between now and September, hundreds - possibly thousands - of post-Leaving Cert students will pack their bags and head off to Spain, Greece or Portugal. They won't be going to improve their language skills or to absorb the local culture. They probably won't even care to sample the traditional tastes of paella or moussaka. They are going for pure, unadulterated fun.

Ask anyone who finished their Leaving Cert four years ago and they'll tell you the only holiday they went on after their exams was with their parents for a wet weekend in Dingle. The phenomenon of mass exodus of pre-college teenagers only began about three years ago, but has already become a rite of passage.

For most, it is a chance to get away for a final bash with friends they have spent the past five years with. It will also be their first holiday that involves neither family nor a stuffy language exchange.

The 65 boys from St Michael's College in Dublin who are going to Spain in August won't even be thinking about such dreaded excursions. Their year got on so well that, way back in January, students organised a holiday in the sun by asking people to write down where they'd like to go. Tenerife was the place and a couple of days after the results in August is the time of departure.

"Go out every night and sleep on the beach during the day," is what Mark O Morain expects to do while away. Robert Murphy acknowledges that there will be some alcohol consumed but he intends to get adventurous and go water-skiing, and jet-skiing. "It's a once-in-a-life opportunity," he says.

"I'll do a bit of clubbing and a load of slobbing around," says Julie Mallon, a student from Laurel Hill in Limerick, who is heading to Gran Canaria in September. Rachael Morden, also from Laurel Hill but going to Santa Ponza, says sunbathing and going out at night are definitely on the cards for her two-week stay in September.

Ann Harrow, a Spanish teacher at St Michael's, doesn't expect her pupils to practise their Spanish during their vacation, but she doesn't consider it a negative exercise. "It seems to be very much the thing to do. It has become a ritual with a lot of them . . . and it keeps them going during the exams," she says.

There won't be much mixing with the locals either, given that most young people meet up with students from other schools. Mark says he'll be looking out for students from the Holy Child School in Killiney, Alexandra College in Dublin and Clongowes, Kildare, while in Tenerife. "It will be like Dublin on a Saturday night," he says. The Laurel Hill girls in Santa Ponza will be meeting up with boys from the Crescent College Comprehensive and St Clement's School in Limerick.

Niamh Hayes, Budget Travel's marketing manager, says the trend is to go away in August or September. The holidays are well-planned: youngsters in school uniforms appear in Budget's offices at the start of the year, and sometimes as early as September the previous year.

Many students work over the summer to save for their trip away, and the end of the summer is their only option. All the money hard-earned in bars, restaurants, petrol stations and corner shops will be blown in two weeks. However, Sinead Dundon from Laurel Hill says she may go to Gran Canaria for just one week instead of two - as she doesn't like the idea of starting college without the all-important money for socialising.

The end of the summer is also the main choice for people worried about re-checks, results and college places. Julie Mallon, who hopes to do medicine at UCD, doesn't think she'll need a recheck but wants to hang around until the first week in September just in case.

If all doesn't go well and he doesn't get the points for architecture, Robert Murphy says the holiday will be a good time to lie on a beach and reflect on his options.

Although Leaving Cert students think a trip to Tenerife, Gran Canaria or Ibiza is the best way to relax after gruelling exams, many of their parents do not agree. Robert Murphy says it took him a while to persuade his parents to allow him to go, and Mark O Morain says some people in sixth year in St Michael's were not so lucky with their parents.

For some parents - no matter what their darling sons and daughters say - the images which flash onto Sky One around this time of year are too much. But do the antics on series such as Ibiza Uncovered really happen?

"Ibiza is an eye-opener," says Laura McNicholas, who went to the resort in 1997 after her Leaving Cert. She says she went to Manumission, reputed to be the biggest night club in the world, and there she ran into all types of wild individuals she probably wouldn't have met at St Joseph of Cluny in Killiney. Laura says Manumission has a "live sex show" at the end of the night, though she didn't stay for it, and there were transvestites touching up their make-up in the toilet.

"Tenerife is not as mad as a lot of other places," says Jenny Harrow, who went there after finishing at Beaufort School, Rathfarnham. She says a lot of young people at the resort were just having a good time, not getting up to any of the unmentionable things clubbers do on the television programmes.

Julie Neeson, travel representative with Budget Travel in Ibiza, says Manumission can be a little shocking but generally only experienced clubbers go there. On the whole, Ibiza is not as scary as it is made out to be, she says. Clubs such as Manumission charge £50 entrance fee, which is too expensive for most Leaving Cert students. "They are all quite young and don't have the money. They try to spread their money around and would instead buy a bottle in a supermarket," says Neeson. The Leaving Cert groups are often very sensible and Budget has never had any trouble with them, she adds.

Some students will venture back to coastal Spain or the Greek Islands again next year but for many, this year's trip will be a last chance to be together before they part ways. Laura McNicholas says other adventures, such as summertime in the US and working holidays in Europe, presented themselves when she started college. Although still good friends with some of the people she went away with, she has drifted away from others. But all Leaving Cert students will no doubt remember the time when the beaches and the bars of Tenerife, Gran Canaria and Ibiza were transformed into meeting houses for eager 18-year-olds from Ireland, all fresh from their exams.