Catherine Boyle salutes the Lammas Fair, a huge, truly cross-community event in Northern Ireland.

Every year, for two days late in August, the small coastal Antrim town of Ballycastle is taken over by between 250,000 and 350,000 visitors, who come to an event that has its origins in the 16th century.

Despite not having an officially integrated agenda, the "ould Lammas Fair in Ballycastle-o" - as the song goes - is one of Northern Ireland's few truly mixed big events.

It has none of the contentiousness of the Twelfth, which has traditionally caused an exodus among middle-class Catholics, but is on a larger scale than community festivals such as West Belfast's Féile an Phobail. As local historian Dr Cahal Dallat says, the fair attracts people from all creeds and classes.

Its widespread appeal is not the result of a concerted effort by cross-community groups or governments, but has evolved naturally over time, despite being held in a predominantly Catholic town.

When asked about this lack of deliberate planning, an employee of Moyle District Council said, "I've never really thought about it, it's just something that happens."

This year, the Lammas Fair takes place today and tomorrow, but the build-up to it began on Friday, with stallholders arriving to claim their patches, and musical events starting. Although the fair is more organised now than in previous years, with Moyle District Council allocating space for stalls, there is still an element of cheerful unruliness to proceedings, as Dr Dallat confirms:

"The council get themselves involved a bit, but no one really stops or starts the Lammas Fair. It's a great way of meeting up with people from year to year. You have old friends that you meet just walking along the seafront."

While other aspects of Northern Irish rural life have declined over the past few decades, the Lammas Fair has continued to attract more and more people every year. Confined to the town's diamond until about 20 years ago, it now spreads along the seafront, the playing fields and down the main street.

Not even a bomb planted in the middle of the 2001 fair by loyalist terrorists, the Red Hand Defenders, could deter visitors from coming back again.

Diane McCook of Moyle District Council attests to the spread of the fair's appeal: "We usually have between 450 and 500 stalls that have space allocated to them before the fair, although we also get people turning up looking for space on the day. People come from all over the North, the South, and from Scotland and Manchester.

"B&Bs and restaurants in the immediate area have been booked up for months - I've been directing people to places 20 miles away, from a month ago. People book for the Lammas from year to year," she adds.

Although sheep-trading - the main focus of the fair in earlier times - has been phased out, horse-trading has grown in recent years.

Stalls sell a bewildering array of products, including CDs, clothing, car accessories, tools, souvenirs, sweets, food, household goods and jewellery.

Ballycastle native Liam Graham, who was involved with the running of the fair for years, highlights its importance to different groups:

"For the traders, it's the last big fair before winter, and for everyone else, it's the last holiday before the kids go back to school. People are marking the passing of summer as the nights draw in. There tends to be two different crowds. On the Monday, which is generally busier, there's a more affluent, bank-holiday crowd. The Tuesday tends to be when the more traditional people come."

Along with every other great Irish event, the Lammas Fair has a ballad commemorating it. It can be heard, here and there, being murdered by revellers, or as part of the fair's ceilís and musical performances.

The song commemorates two of the fair's culinary traditions: Yellow Man and Dulse. Yellow Man is a sticky sugar and syrup concoction guaranteed to give your dentist a coronary, and a great weapon in inter-sibling battles. Dulse is a savoury snack to go along with it - it's a dried, reddish, very salty seaweed.

Although the fair itself has changed and grown, these elements mark a constancy with the past that will hopefully continue with the unruly, all-embracing spirit that is the essence of the Lammas Fair's appeal.