Mud Day Queen Riley Tulgetske, left, embraces Mud Day King Phoenix Crowder during Mud Day at the Nankin Mills Park, Tuesday, July 9, 2019, in Westland, Mich. The annual day is for kids 12 years old and younger. While parents might be welcome, this isn't an event meant for teens or adults. It's all about the kids having some good, unclean fun during their summer break and is sponsored by the Wayne County Parks. (Photo by Carlos Osorio/AP Photo)

Hadeel, 10, asks a passerby for help to pay a medical bill as her father Shahrour, 54, sits in his wheelchair in the Douma neighbourhood of Damascus Syria February 3, 2016. Shahrour said he developed diabetes at the beginning of the war in Syria. A lack of insulin led to his medical condition worsening and his right foot had to be amputated. Recently he also suffered a stroke that paralysed half his face. He and part of his extended family, a total of 18 people, live together and struggle to get by. (Photo by Bassam Khabieh/Reuters)

A member of Alfama's group is seen before going to the Saint Anthony's Parade in Lisbon, Portugal June 12, 2016. (Photo by Rafael Marchante/Reuters)

Each year Nikon Small World recognizes the excellence of photography taken under the microscope. The contest showcases the beauty and complexity of life. Anyone interested in microscopy and photography can enter the contest and in its 42nd year, Nikon Small World received 2,000 entries from 70 countries. Here: 11th Place; Scales of a butterfly wing underside (Vanessa atalanta). (Photo by Francis Sneyers/Nikon's Small World 2016)

Photographer Mihaela Noroc travelled the world from Ethiopia to the US and from Guatemala to France in search of natural and authentic beauty. She introduces some of the inspiring women she met on her journey. Here: Ecuador. “More and more tribes of Amazonia are starting to adopt modern clothes for everyday life. But they are still keeping their traditional clothes for important events. I photographed this young woman in her wedding outfit”. (Photo by Mihaela Noroc/The Guardian)

Walkers cross the river Waalbrug during the first day of the 98th annual four-days walking event, the “Vierdaagse” in Nijmegen, Netherlands, July 15, 2014. The “Nijmeegse Vierdaagse” is an annual public four-day field march which is held since 1909 in the third week of July. (Photo by Erik van 't Wout/EPA)

Photochromes are vibrant and nuanced prints hand-coloured from black-and-white negatives. Created using a process pioneered in the 1880s, these images offer a fascinating insight into the world when colour photography was still in its infancy. A Tour of the World in Photochromes is at the Swiss Camera Museum, Vevey, until 21 August. Here: Street food in the Strada del Porto in Naples, Italy, 1899. (Photo by Swiss Camera Museum/The Guardian)

A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)