Mount Nyiragongo is an active stratovolcano On the Virunga Mountains associated with the Albertine Rift. It is located inside Virunga National Park, in the Democratic Republic of the Congo, about 20 km (12 mi) north of the town of Goma and Lake Kivu and just west of the border with Rwanda. The main crater is about two km wide and usually contains a lava lake.

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)

Renee LeGrand, of Foothill Ranch, Calif., takes a picture among wildflowers in bloom Monday, March 18, 2019, in Lake Elsinore, Calif. About 150,000 people flocked over the weekend to see this year's rain-fed flaming orange patches of poppies lighting up the hillsides near Lake Elsinore, a city of about 60,000 residents. The crowds became so bad Sunday that Lake Elsinore officials closed access to poppy-blanketed Walker Canyon. By Monday the #poppyshutdown announced by the city on Twitter was over and the road to the canyon was re-opened. (Photo by Gregory Bull/AP Photo)

Children hold signs thanking truck drivers hauling rocks to the Lake Oroville Dam after an evacuation was ordered for communities downstream from the dam in Oroville, California, U.S. February 13, 2017. (Photo by Jim Urquhart/Reuters)

A little red flying fox dips a toe in a lake at the mouth of Katherine gorge in the Northern Territory, Nitmiluk national park, Australia on September 20, 2017. (Photo by Glenn Campbell/AAP)

A pool ingeniously filled with clear water in the middle of Lake Kerniki in Greece enabled this shot of feeding pelicans. (Photo by Bence Mate/Close Up Photographer of the Year 2020)

A great crested grebe feeds a chick sitting on its mother’s back on a lake in Cáceres, Spain. (Photo by Jose Luis Ruiz/Solent News & Photo Agency)

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)