Lughnasadh is mentioned in some of the earliest Irish literature and has pagan origins. The festival itself is named after the god Lugh. It involved great gatherings that included religious ceremonies, ritual athletic contests (most notably the Tailteann Games), feasting, matchmaking and trading. There were also visits to holy wells. According to folklorist Máire MacNeill, evidence shows that the religious rites included an offering of the ‘first fruits’, a feast of the new food and of bilberries, the sacrifice of a bull and a ritual dance-play in which Lugh seizes the harvest for mankind and defeats the powers of blight. Much of the activities would have taken place on top of hills and mountains. (from Wikipedia)

Originally it was held on 1 August, or about halfway between the summer solstice and autumn equinox. However, over time the celebrations shifted to the Sundays nearest this date

This is a celebration of the early harvest. Many traditions and myths surround this season. Climbing to the top of a hill or mountain, giving the first fruits or harvest as offerings of thanks, mock battles or games that test strength and courage.

Midsummer, also known as St John’s Day, is the period of time centred upon the summer solstice, and more specifically the Northern European celebrations that accompany the actual solstice or take place on a day between June 19 and June 25 and the preceding evening.

This is a time to celebrate the sun and the blooming, ripening and flourishing all around. Decorating the nature table and house with flowers, images of light and sun and great ways to bring in the season. Bring golds, yellows and fiery colors to the nature table or alter. Spending extra time outdoors, picnicking, camping or just playing at the park. Also there are many wonderful crafts to do in this season that celebrate the sun and summer.