“Misty Morning”. Every morning, people expect sunny weather. Photo location: Bali, Indonesia. (Photo and caption by Henry Adam/National Geographic Photo Contest)

In this photo taken Tuesday, October 14, 2014, skulls and bones are stacked at the Catacombs in Paris, France. The subterranean tunnels, stretching 2 kilometers (1.24 miles), cradle the bones of some 6 million Parisians from centuries past and once gave refuge to smugglers. The site used to close at 5 p.m., but is now staying open until 8 p.m. The change is mainly aimed at allowing more people to visit and reducing long lines, since it can only hold a limited number of people at a time and visits can't be reserved in advance. (Photo by Francois Mori/AP Photo)

Tourists wear protective masks in Sanur, Bali, Indonesia, 15 March 2020. Indonesia has around 80 active cases of Covid-19. More than 70,000 people worldwide have recovered from coronavirus, nearly half of the total infections recorded since the outbreak began. (Photo by Made Nagi/EPA/EFE)

People look at a black bear at the Chengdu zoo amid the coronavirus outbreak on March 26, 2020 in Chengdu, Sichuan Province of China. (Photo by Wang Lei/China News Service via Getty Images)

People wear face masks to protect against the coronavirus as they walk across an intersection in Beijing, Friday, June 5, 2020. China on Friday reported five new confirmed coronavirus cases, all of them brought by Chinese citizens from outside the country. (Photo by Mark Schiefelbein/AP Photo)

A vendor pushes an improvised cart with a woman and merchandise along a rarely used rail track in Bangkok, Thailand, Thursday, June 25, 2020. Daily life in the capital slowly returns to normal as the Thai government eases many restrictions imposed weeks ago to combat the spread of COVID-19. Though emergency regulations require the use of face masks in public, some residents have become apathetic as Thailand has record zero local transmission for over three weeks. (Photo by Gemunu Amarasinghe/AP Photo)

Ariana Lamcellari, 4, holds a sign at a protest against violence, following the charge of a British police officer in the London kidnapping and murder of Sarah Everard, in Dublin, Ireland on March 16, 2021. (Photo by Clodagh Kilcoyne/Reuters)

A health worker applies a dose of the AstraZeneca vaccine during the first day of a three-day COVID-19 vaccination campaign for people over age 35 in the Complexo da Maré favela of Rio de Janeiro, Brazil, Brazil, Thursday, July 29, 2021. Some recipients will be monitored to study the rate of protection the vaccines provide and the extent to which virus variants are circulating. (Photo by Bruna Prado/AP Photo)