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 man wearing an illuminated atmospheric diving suit as part of an installation titled “What Lies Beneath” looks at members of the public during the Vivid Sydney festival of light and sound in Sydney, Australia, May 26, 2017. (Photo by Steven Saphore/Reuters)

The Historic Photographer of the Year awards celebrate historic places and cultural sites across the globe, from national treasures to hidden gems. Entries were judged on originality, composition and technical proficiency as well as the story that inspired the submission and its historical impact. Here: Overall winner. Mont Saint-Michel by Daniel Burton. (Photo by Daniel Burton/The Guardian)

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)

In this Sunday, June 27, 2010 file photo two men compete in an ostrich race at Highgate ostrich farm in Oudtshoorn, South Africa. Clambering onto an ostrich for a ride used to be popular among tourists in a South African town of Oudtshoorn known of as the “ostrich capital of the world”. Not so much anymore. Two major ostrich farms in Oudtshoorn have stopped offering ostrich rides to tourists, responding to concerns about the birds’ welfare. A third farm is sticking with the feature, saying it is regulated and that ostriches do not experience discomfort. The Highgate farm, however, continues to offer ostrich rides. (Photo by Shuji Kajiyama/AP Photo)

A displaced Yemeni woman from Hodeida fills water containers at a make-shift camp in a village in the northern district of Abs in the country's Hajjah province, on May 9, 2019. The Yemeni conflict has triggered what the United Nations describes as the world's worst humanitarian crisis, with 3.3 million people still displaced and 24.1 million in need of aid. (Photo by Essa Ahmed/AFP Photo)

As the world marks the International Day of the Girl Child, women's rights activists point to progress on a wide array of issues but say more needs to be done to protect girls from child marriage, sexual assault and other forms of exploitation. Here is a selection of pictures showing the daily lives of girls across the globe, all taken by female Associated Press photojournalists. Here: In this December 14, 2015, file photo, a young clown rides in the back of a car following a procession to the Basilica of Our Lady of Guadalupe in Mexico City. Hundreds belonging to various clown associations made their annual pilgrimage to the Basilica to pay their respects to the Virgin of Guadalupe, Mexico's patron saint. (Photo by Rebecca Blackwell/AP Photo)

Four actors on horseback dressed in Game of Thrones related costumes carry the Queen's Baton as they make their way way along the Dark Hedges on August 29, 2017 in Antrim, Northern Ireland. The Dark Hedges near Stranocum in County Antrim featured as the King's Road in season two of Game of Thrones and has become a tourist mecca for fans of the television series along with other filming locations in the province. The Queen's Baton Relay is currently on a tour of the United Kingdom as it makes its way around Europe in preparation for the 2018 Commonwealth Games in Australia. (Photo by Charles McQuillan/Getty Images)