The Spanish photographer Xavi Bou digitally combines sequential pictures of birds to create a single image, or chronophotograph, that reveals the shapes of their flight paths against Catalonian skies. His work shows the variety and beauty to be found in the daily activities of the local birds, including spiralling storks, swooping starlings and giddy swifts. Here: European herring gulls at Llobregat Delta. (Photo by Xavi Bou/Rex Features/Shutterstock)

“Mount Hua, or Hua Shan, or Xiyue located near the city of Huayin in Shaanxi province, about 120 kilometres (75 mi) east of Xi'an. It is one of China's Five Great Mountains, and has a long history of religious significance. Originally classified as having three peaks, in modern times the mountain is classified as five main peaks, of which the highest is the South Peak at 2,154.9 metres (7,070 ft)”. – Wikipedia

Photo: Trip to Xi'an 西安. (Photo by Grant Robinson)

Festivalgoers watch two actors of the Wasteland Warriors movement fight in a cage at the world's largest heavy metal festival, the Wacken Open Air 2019, in Wacken, Germany on August 3, 2019. Wacken is a village in northern Germany with a population of 1,800 that has hosted the annual festival, which attracts heavy metal fans from around the world, since 1990. (Photo by Wolfgang Rattay/Reuters)

Dinara Safina of Russia hits a backhand in her match against Arantxa Parra Santonja of Spain during the BNP Paribas Open at the Indian Wells Tennis Garden on March 10, 2011 in Indian Wells, California.

Sorana Cirstea of Romania hits the ball against Jie Zheng if China during the Sony Ericsson Open at Crandon Park Tennis Center on March 22, 2011 in Key Biscayne, Florida.

The Queen Mary 2 is saluted by the HMB Endeavour, the replica of Captain James Cook's ship, on March 4, 2012 off the coast of Victoria, Australia. (Photo by James Morgan/Carnival Australia via Getty Images)

Plastinated human corpses posed to look like poker players stand on display at the Body Worlds exhibition on April 27, 2011 in Berlin, Germany. The exhibition, which features human and animal corpses plastinated by Gunther von Hagens, focuses on the role of the heart. It will be open to the public at the Postbahnhof from April 27 to August 14. (Photo by Sean Gallup/Getty Images)

Dancers perform during the opening ceremony before the Russia 2018 World Cup Group A football match between Russia and Saudi Arabia at the Luzhniki Stadium in Moscow on June 14, 2018. (Photo by Sergei Bobylev/TASS via Getty Images)