Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Hindu pilgrims walk along a mountain path as they make their pilgrimage to the sacred Amarnath Cave, one of the most revered Hindu shrines, near Baltal, Kashmir, India. (Photo by Daniel Berehulak)

A bench engraved with the name of the grounded Costa Concordia cruise ship (seen at rear) is seen washed up on the shore of Giglio island, in this January 20, 2012 file photo. The trial of Francesco Schettino, accused of causing the deaths of 32 people in the 2012 Costa Concordia cruise ship disaster, nears its climax with a verdict expected over the coming days. The prosecution has demanded that he be jailed for 26 years but the captain denies all the charges against him. Schettino was the commander of the vessel when it came too close to shore and hit rocks off the Tuscan holiday island of Giglio. (Photo by Paul Hanna/Reuters)

“Sunward”. When the Mediterrenean Mantis opened its wings, It seemed very impressive at the sunshine... Photo location: Nicosia, Cyprus. (Photo and caption by Hasan Baglar/National Geographic Photo Contest)

Lazar and his sister Andjelka sit by a candle in their home in the eastern Serbian town of Majdanpek, December 4, 2014. Electricity workers in Serbia struggled through snow, ice and treacherous terrain on Thursday to restore electricity to an eastern town left shivering without power, heating or running water for a fourth day. (Photo by Marko Djurica/Reuters)

“LSD Photo Advertising Studio is comprised of Marco and Paolo. They are photographers who compose, shoot and post-produce all of their images together. For over ten years, they have been creating images from start to finish. Marco and Paolo have different backgrounds of experience: Paolo started as an illustrator then a photographer, and now he’s at Marco’s side and in his head throughout shooting. In turn, Paolo does all the post-production with Marco in his head and at his side. Marco has always worked as photographer”. – Tim Mitchell

“An electronic cigarette, or e-cigarette, is an electrical device that simulates the act of tobacco smoking by producing an inhaled mist bearing the physical sensation, appearance, and often the flavor and nicotine content of inhaled tobacco smoke; though without its odor, and intended to omit its health risks. The device uses heat (or in some cases, ultrasonics) to vaporize a propylene glycol- or glycerin-based liquid solution into an aerosol mist, similar to the way a nebulizer or humidifier vaporizes solutions for inhalation”. – Wikipedia

Photo: Owner of a shop that sells electronic cigarettes demonstrates how to use one on March 1, 2012 in Berlin, Germany. The German government has announced that it classifies the liquids used in electronic cigarettes as pharmaceuticals because the liquids contain nicotine, and that sale of the liquids requires certification. (Photo Illustration by Sean Gallup/Getty Images)