Modern pagans celebrate the wheel of the year with eight seasonal holidays-the solstices and equinoxes and the cross-quarter-days in between. The ancient Celtic festival Lughnasa (pronounced loonasah), falling midway between summer solstice and autumn equinox, marks the end of summer and the beginning of the harvest. The Anglo-Saxons called it Lammas, for loaf-mass, after the blessing of bread, made from the first harvest of grain. Today, most pagans observe the holiday on August 1.

The 1990 play "Dancing at Lughnasa" (later a movie starring Meryl Streep) depicts the melancholy that underlies this festival, the sorrow at the end of summer, the sacrifice that comes with cutting the grain.

In ancient times, Lughnasa was also the time of an assembly in honor of the Celtic hero-god Lugh (nasad means assembly). The poet Cuan o'Lothchain wrote in 1007 that the purpose of the assembly was to provide corn, milk, good weather, and peace, and that Ireland will always have song as long as the assembly is held.

At the famous assembly in Leinster, Ireland, which was held in August every third year and lasted for seven days, a poem was written in 1040 to celebrate the fair. This description gives a flavor of what it must have been like:

Three busy markets on the ground,
A market of food, a market of live stock,
The great market of the Greek strangers
Where there is gold and fine raiment.
The slope of the horses, the slope of the cooking,
The slope of the women met for embroidery.

Folklorist Maire MacNeill wrote a book about Lughnasa, looking for clues about the origins of the festival from a variety of sources including a survey administered in Ireland in 1942. As a folklorist, I always look at the simple, earth-based folk customs that persist for the core themes of the holiday.

This holiday has many names, including Bron Trogain, sometimes translated as "earth sorrows under her fruits." Other names refer to customs associated with the holiday like Garlic Sunday, Black Crom's Sunday, the Last Sunday of Summer, the First Sunday of Autumn, Bilberry Sunday, and Garland Sunday.

Climbing a mountain is one of the most characteristic aspects of Lughnasa. People climbed mountains all over Ireland, often picking bilberries as they go, thus giving rise to the popular name of Bilberry Sunday. Bilberries are one of the first berries to ripen in Ireland (today, where I live in Seattle, we're more likely to be harvesting the first blackberries). In some places, boys threaded the berries on grass stalks and make bracelets of them for the girls of their choice. In Cashel Plantin' in County Armagh, these strung berries were brought home as presents and kept around the house for luck.

In County Mayo, people wore garlands made from the stalks of corn. In other places, the garlands were fashioned from flowers and left on mountain tops, along with other offerings such as wheat. At Gainmhe in County Donegal, everyone wore a flower going up hill and at the summit all the flowers were put into a hole and covered over, as a sign that summer was over.

Since many scholars believe Lugh was a sun-god, it makes sense that people would climb mountains and leave offerings for him in high places. But some believe the offerings were left for the fairies, who would be extraordinarily active on quarter days. MacNeill believes the practice of standing on a peak overlooking the landscape, keeps alive a passion for the land and its history.

Many of the customs of Lughnasa have slowly faded away over the centuries, but some traditions are still honored. It's said to be lucky to harvest new potatoes on Lughnasa and unlucky to dig them up earlier. The farmers of Ballinrobe, County Mayo, said there were three things a good farmer should have left on Garlic Sunday: a stack of unthreshed oats, a stack of old turf, and a pit of old potatoes (thus showing his ability to properly allocate his resources).

It's also traditional to have the potatoes for dinner on Lughnasa, often with bacon and cabbage, or in Colcannon (a dish of potatoes, mixed with butter or milk and seasoned with garlic, onion or cabbage).

And pilgrims still climb Mount Brandon on the last Sunday in July, circumambulating the ruined medieval church and the nearby well, under the watchful eyes of a sculpture of Crom Dubh, the Celtic god of harvest.

If you want to honor this ancient holiday, incorporate these Lughnasa traditions into your celebrations:

Hike to a mountaintop where you can overlook the land

Gather flowers and leave them as an offering to the sun god, or the fairies. You could also bury them or burn them as a sign that summer has passed

Go berry picking

Enjoy new potatoes, or whatever you harvest from your garden

Dance and sing around a bonfire