Revellers celebrate the pagan festival of Summer Solstice at Stonehenge in Wiltshire, southern England on June 21, 2015. The festival, which dates back thousands of years, celebrates the longest day of the year when the sun is at its maximum elevation. Modern druids and people gather at the landmark Stonehenge every year to see the sun rise on the first morning of summer. AFP PHOTO/NIKLAS HALLE'N        (Photo credit should read NIKLAS HALLE'N/AFP/Getty Images)