Lady Gaga attends Billboard's 10th Annual Women In Music at Cipriani 42nd Street on December 11, 2015 in New York City. (Photo by Grant Lamos IV/Getty Images)
Fighters of the pro-government Popular Resistance Committees militia carry a cannon as they transport it in parts to Yemen's southwestern war-torn city of Taiz December 26, 2015. (Photo by Reuters/Stringer)
Fighters of the Popular Resistance Committees stand during a graduation ceremony of the affiliate special forces of the Popular Resistance, in Yemen's southwestern city of Taiz October 8, 2015. (Photo by Reuters/Stringer)
Bison along the Bitterroot Valley's Eastside Highway north of Stevensville, Montana, are covered in snow following a blizzard on November 23, 2010. (Photo by Perry Backus/The Missoulian)
White smoke billowed from the chimney on the Sistine Chapel indicating that a new pope has been elected in St. Peter's Square at the Vatican, Wednesday, March 13, 2013. (Photo by Dmitry Lovetsky/AP Photo)
“I'm very lucky to be in a wonderful part of England , where the ever changing sky's are always a new opportunity for a good shot. To me photography is the art of using light to one's advantage”. – Eric Goncalves. Photo: “Let the light enter”. (Photo by Eric Goncalves)
La Traviata chandelier is positioned on stage at Mrs Macquarie's Point on March 16, 2012 in Sydney, Australia. Covered with 10,000 Swarovski crystals, the 9 metre high chandelier will be hung above the performing stage of the La Traviata Opera. (Photo by Brendon Thorne/Getty Images)
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.