Cave Diver, Anhumas Abyss, Bonito, Brazil: The Anhumas Abyss is an underground cavern with a crystal-clear lake below, more than 260 feet (79 m) deep. A visitor must enter through a narrow opening at the top of the chamber and rappel into the cave. Snorkeling and scuba diving in the lake reveal amazing scenery. Distinctive, conical limestone stalagmites and stalactites occupy the lake and the surrounding area, some reaching 65 feet (20 m) high. (Photo by Marcio Cabral/Nature’s Best Photography Awards 2017)

Local people check the growth of mussels at a river in Haian County on November 2, 2017 in Nantong, Jiangsu Province of China. Fish, shrimp, crab and mussel farming cleans the river and increases the villagers' income at Haian county in Jiangsu. (Photo by VCG/VCG via Getty Images)

Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. (Photo by Mario Tama/Getty Images)

In this November 30, 2017 photo, Douglas scoops up mud from the bottom of the polluted Guaire River, in search of gold and anything valuable he can sell, in Caracas, Venezuela. Some stretches of the river smell of sewer while others emit a toxic odor of fuel, a stench that stays in ones nose for hours after leaving the water. (Photo by Ariana Cubillos/AP Photo)

A model rehearses with a fabric face mask on, designed by Zhou Li for her Autumn/Winter 2020 collection show, during China Fashion Week in Beijing, following the novel coronavirus disease (COVID-19) outbreak, China on May 3, 2020. (Photo by Tingshu Wang/Reuters)

Tourists wearing protective face masks walk in Nanluoguxiang alley, a famous touristic spot at Hutong neighborhood, in Beijing, China, 01 May 2020. China is loosening up nationwide restrictions after months of lockdown over the coronavirus crisis. Labor Day in the country kicked off with a long weekend and an extended holiday, from 01 to 05 May, after the tourism industry has been hit during the coronavirus and COVID-19 disease pandemic. (Photo by Roman Pilipey/EPA/EFE)

Kazakh girls watch as the Russian Soyuz TMA-15 rocket carrying Canadian astronaut Robert Thirsk, European Space Agency (ESA) astronaut Frank De Winne of Belgium and Russian cosmonaut Roman Romanenko readies for take-off from the Baikonur cosmodrome, in Kazakhstan on May 27, 2009. Three astronauts, from Canada, Belgium and Russia, blasted off for the International Space Station in a landmark mission that will double its crew to six for the first time. (Photo by Dmitry Kostyukov/AFP Photo)

Ride operator Van Mai wears a face mask against the spread of the coronavirus while working at the Playland amusement park at the Pacific National Exhibition, in Vancouver, British Columbia, Friday, July 10, 2020. (Photo by Darryl Dyck/The Canadian Press via AP Photo)