The festival is primarily a Celtic fire festival, representing the middle of summer, and the shortening of the days on their gradual march to winter. Midsummer is traditionally celebrated on either the 23rd or 24th of June, although the longest day actually falls on the 21st of June. The importance of the day to our ancestors can be traced back many thousands of years, and many stone circles and other ancient monuments are aligned to the sunrise on Midsummer's Day. Probably the most famous alignment is that at Stonehenge, where the sun rises over the heel stone, framed by the giant trilithons on Midsummer morning.
In antiquity midsummer fires were lit in high places all over the countryside, and in some areas of Scotland Midsummer fires were still being lit well into the 18th century. This was especially true in rural areas, where the weight of reformation thinking had not been thoroughly assimilated. It was a time when the domestic beasts of the land were blessed with fire, generally by walking them around the fire in a sun-wise direction. It was also customary for people to jump high through the fires, folklore suggesting that the height reached by the most athletic jumper, would be the height of that years harvest.