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)

Bulgarian Muslims Azim Liumankov and his bride Fikrie Bindzheva pose in front of their house during their wedding ceremony in the village of Ribnovo, in the Rhodope Mountains, February 15, 2015. The remote mountain village of Ribnovo in southwest Bulgaria has kept its traditional winter marriage ceremony alive despite decades of Communist persecution, followed by poverty that forced many men to seek work abroad. (Photo by Stoyan Nenov/Reuters)

The Andromeda Galaxy, the nearest major galaxy to the Milky Way, can be seen shining above a remote village in Switzerland. The cinematic images convey the beauty of the galaxy gleaming above the picturesque Swiss mountains. Photographer Sandro Casutt took the amazing snaps in different seasons throughout the year, from his home valley of Vals, Switzerland. Here: A view of the sky from the Zervreila Mountain Lagoon in Switzerland. (Photo by Sandro Casutt/Caters News)

Security personnel patrol around West Lake in Hangzhou, Zhejiang Province, China, August 31, 2016. (Photo by Reuters/Stringer)

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)

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 man covered with mineral-rich mud smiles on a bank of lake Tus in Khakassia region, southwest of the Siberian city of Krasnoyarsk, Russia, July 16, 2016. (Photo by Ilya Naymushin/Reuters)

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)