Lava gushes from the southern side crater of Mt. Etna, Europe's largest active volcano, near Catania, southern Italy Sicily, early Tuesday, May 25, 2021. (Photo by Salvatore Allegra/AP Photo)

A military instructor teaches a schoolboy shooting with Kalashnikov rifles, during a training session at a military unit of the National Guard of Ukraine in western Ukrainian city of Lviv on February 15, 2022. (Photo by Yuriy Dyachyshyn/AFP Photo)

Syrian dancer and choreographer Yara al-Hasbani performs a dance on the empty Trocadero square in front of the Eiffel tower in Paris on April 22, 2020, on the 37th day of a strict lockdown in France to stop the spread of COVID-19 (novel coronavirus). (Photo by Sameer Al-Doumy/AFP Photo)

A colorful sky at sunset over the snowy mountains in Immenstadt, Bavaria, Germany, 20 November 2014. Cloudy weather is forecast in the region on 21 November. (Photo by Karl-Josef Hildenbrand/EPA)

Adventurer Sam Cossman movies towards the huge lava lake wearing a custom built industrial proximity heat suit on December 20, 2014 in Ambrym, Vanuatu. (Photo by Conor Toumarkine/Barcroft Media)

A woman controls a ball on Ipanema beach in Rio de Janeiro, Brazil, April 14, 2016. As hundreds of thousands of tourists begin descending on Rio de Janeiro for the Olympics that start August 5, the headlines have focused on the street violence, the Zika virus, the water pollution and the rush to finish venues and transport. But Rio, known by Brazilians as the “Marvelous City”, glistens despite it all. The beach is a way of life here. (Photo by Nacho Doce/Reuters)

British holidaymaker Sean Chinn captures a crocodile on camera during a dive at the Jardines de la Reina marine park in Caribbean Sea, Cuba. (Photo by Sean Chinn/Caters News Agency)

“Himalayan Dog”. This dog just appeared out of nowhere and followed us for an entire week during our trekking trip in the Himalayan outback. He always used to sleep in front of our tent and guarded us in the nights. When I decided to get up at 4 a.m. to climb the next 5000 m peak for sunrise he accompanied me as well. On the top he was sitting for the entire 30 minutes on this place looking straight into the countryside. Photo location: Ladakh, India. (Photo and caption by Sebastian Wahlhuetter/National Geographic Photo Contest)