Guests on the terrace of Shepheard's Hotel, Cairo, circa 1940. (Photo by Hulton Archive/Getty Images)

A dramatic sunset acts as a backdrop to Stonehenge on November 20, 2008 in Stonehenge, England. (Photo by Mike Hewitt/Getty Images)

An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

An aerial view of the holy Muslim Shiite shrine of Imam Moussa al-Kazim as pilgrims gather to commemorate his death, in the Shiite district of Kazimiyah, Baghdad, Iraq, Wednesday, May 13, 2015. The anniversary of 8th century Shiite Imam Moussa al- Kazim drew tens of thousands of Shiites from all walks to converge on his golden-domed shrine in northern Baghdad. The pilgrims typically march to the shrine while hundreds of tents are erected to offer them free food, drinks and services. (Photo by Hadi Mizban/AP Photo)

An injured NATO soldier lies on the ground following a suicide car bomb attack that targeted foreign military vehicles in the Afghan capital Kabul on June 30,2015. A powerful blast hit downtown Kabul on June 30 as a suicide car bomber targeted foreign military vehicles, officials said, with casualties feared. The blast came on the main road to the airport, around 500 meters (550 yards) from the US embassy and near a base for foreign troops.“It was a suicide car bomber targeting a convoy of foreign forces in Kabul”, interior ministry spokesman Sediq Sediq said. (Photo by Wakil Kohsar/AFP Photo)

Runners hoist another runner into the air after completing The Color Run All-Star 5K as part of the All-Star Baseball game festivities, Saturday, July 11, 2015, at Sawyer Point Park, in Cincinnati. After more than two years of planning and sprucing up, city organizers say everything's in place for a smooth, safe and fun five days of events that began Friday morning with the opening of Major League Baseball's fan festival. There will be concerts, exhibits, celebrity softball, the Home Run Derby and other activities capped by Tuesday night's game. (Photo by John Minchillo/AP Photo)

Britain's Chris Froome, wearing the overall leader's yellow jersey, is followed by Spain's Alberto Losada, Italy's Vincenzo Nibali and Spain's Alejandro Valverde as they speed downhill during the seventeenth stage of the Tour de France cycling race over 161 kilometers (100 miles) with start in Digne-les-Bains and finish in Pra Loup, France, Wednesday, July 22, 2015. (Photo by Christophe Ena/AP Photo)

People help a wounded person after Yishai Schlissel, an ultra-Orthodox Jew, attacked people with a knife during a gay pride parade in Jerusalem on Thursday, July 30, 2015. Schlissel lunged into a group of revelers leading Jerusalem's annual gay pride parade and stabbed several of them Thursday evening as they marched in the holy city, Israeli police and witnesses said. (Photo by Sebastian Scheiner/AP Photo)