After a grueling week of foreign policy crises that must have often seemed like trying to push boulders up a mountain, President Obama took a surprise detour on the way home. Marine One flew him halfway across England so he could walk amid the mysterious and awe-inspiring boulders of Stonehenge.

"Spectacular" he kept saying.

The president walked alone amid the towering slabs at sunset, humbled.

"How cool is this?" he asked.

The ring of stones have been dated back to before 2000 BC, with few clues as to how prehistoric hands were able to move them into their circular setting.

Clouds made the scene appear somewhat haunting, and most tourists seemed to be kept away, giving the president a few moments of peace. He expressed surprise that Stonehenge was smaller than it appeared as he flew in.

Before he turned to go, President Obama sounded satisfied.

"Knocked this off my bucket list," he said.