SALISBURY, England—Over a cup of coffee at a recent meeting of the Round Table, the managers of Stonehenge learned that King Arthur Pendragon, the Chosen Chief of the Loyal Arthurian Warband Druid order, was preparing his warriors for battle.

At stake: free parking.

For years, Mr. Pendragon, Druid King of Britain, has parked his ancient Kawasaki motorbike on a dirt track just off the A303 highway and walked the short distance across a field to conduct ceremonies at this ancient stone circle.

Now, English Heritage, the government unit that manages the site and other landmark buildings and monuments, wants to stop him and others from parking so close to the stones.

"I work at Stonehenge as a Druid," the 60-year-old Mr. Pendragon says. "English Heritage are acting like spoiled brats."