You have been invited to attend the most incredible sunrise wedding, the nuptials of Heaven and Earth. God, the Sun King, has asked the Goddess, Mother Earth, to take his hand in holy matrimony. This is the way the Druids view daybreak on the Summer Solstice. Appropriate attire for this event is a white robe. However, almost anything else goes.
Get a book about the Druids, and use it to figure out how they dressed. Try a book like "Bonewits's Essential Guide to Druidism" by Isaac Bonewits at Amazon.com (see Resources below).
Wear an accurate Druid costume. The typical outfit at Stonehenge consists of a long, white, flowing poly-cotton robe. It is covered with a white, ground-length tunic of a thicker material.
View a definite sprinkling of Summer Solstice attendees wearing tunics of black/brown/green, red/blue and silver/gold, representing ranks among the present-day Neopagan Druids.
Take a white hood, which attaches loosely to your robe. Wear sweatshirts and warm pants under your white robe. This will help you stay warm when the sun goes down and it gets cold.
Don a sprig of mistletoe and your Druid sigil. A Druid sigil is a circle, usually a wreath, with two lines running straight through it, in a parallel fashion. Wear your sigil in the form of a silver pin and attach it to your robe, carrying the mistletoe in your hands.
Dress in an elaborate costume. Revelers often dress in costumes decorated with crowns, helmets, breastplates, rings and a range of tools.
Dress as a pirate. This is a popular costume among men who celebrate Summer Solstice at Stonehenge.
Wear your regular clothing. You won't be turned away, as there is no official dress code for this event.
Put on comfortable shoes. You may be on your feet for much of the Stonehenge celebration.
Attend this event without cash-flow worries. Both parking and the festival are free of charge. Observe the rules. Camping, dogs, fires, fireworks, glass bottles, large bags and rucksacks are not allowed. Also, revelers are not allowed to climb onto the stones.
Don't plan on sleeping Friday night. Attendees stay up all through the night, chatting and celebrating.