Tomorrow is officially the longest day of the year, when the Sun is at its highest point of the year in the northern hemisphere. In ancient pagan times the Summer Solstice was hugely significant, it was a time when the power of the Sun was at its highest and was seen as an important time for fertility, when the harvests of the coming year were blessed. It was also believed that certain plants had miraculous healing powers when picked on this night. Bonfires were lit to protect against evil spirits believed to roam freely when the sun was turning southwards again. Witches are also thought to rendezvous with powerful beings on this day.