I got this from care2.com:
The History of Midsummer
Once dedicated to the Norse fertility goddess Freya, dating back to the 5th century, the longest day of the year is today celebrated on the weekend closest to June 24, St. John the Baptist’s Day. Throughout Sweden, families and friends gather to decorate the maypole with birch leaves and wildflowers, make flower crowns for women and girls, dance around the maypole, sing summer songs and feast on pickled herring, new potatoes, strawberries and aquavit.
According to an ancient rite, sunrise or sundown on Midsummer’s Day is an auspicious time to gather together a magical bouquet consisting of seven different flowers. You have to pick the flowers naked, alone and under silence. By “sleeping on the bouquet” (inside or underneath the pillow), boys and girls will then receive dreams about their future mate.
Today, Witches and Pagans also celebrate Midsummer as a time rife with divinations, healing rituals, and the cutting of divining rods and wands. Witches and Pagans still believe the “Little People” exist in great numbers during this balance of light and dark. It is said that standing in a fairy ring will help you to see them, if they like you.