The Lammas Fair, or 'the Oul' Lammas Fair', takes place on the last Monday and Tuesday in August，in Ballycastle Northern Ireland. It is famed for having an 'unbroken history', having taken place annually for the past 300 years but its origins go back to the local legends and myths.  

The name of Lammas originated from the 'Feast of Lughnasadh'  or Lugh (Lu). Lugh was in legend a Sun God who had a mortal foster mother called Tailtiu, who in turn was a queen or princess in the firbolgs. The firbolgs (Meaning of the word is 'Men of Bags') were early inhabitants of the place and are said to have come from Greece or Spain. Later they were invaded and ruled by the people of Dana (Tuatha de Danna).

The Dana forced Tailtiu to clear a large area of woodland for the planting of grain and she died of exhaustion in the process. She was buried under a great mound which was called the ‘Hill of Tailtiu’ and Lugh instructed that each year a festival be held to commemorate his foster mother’s death, where there should be games and the feasting on the first fruits of the harvest.

With the arrival of Christianity and its dominance as a faith, we find the festival of Lugh changing and adopting more  Christian symbolisms, loaves of bread baked from the first harvest grain are placed on the church altar. The 'Christianised' name for the festival of Lugh becomes Lammas which means 'loaf mass'.  

Today's Lammas is a time of stalls, buying and selling, traditional music and horse trading, a local tradition exists of eating yellow candy called 'Yellow Man' and eating 'Dulse', a reddish sea weed of the variety 'Palmaria palmata' which has been eaten and used in medicine for centuries. The 'Oul Lammas Fair' attracts people in their thousands from all over the world.

Source:http://www.northantrim.com