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.

A relic hunter dubbed “Indiana Bones” has lifted the lid on a macabre collection of 400-year-old jewel-encrusted skeletons unearthed in churches across Europe. Art historian Paul Koudounaris has hunted down and photographed dozens of gruesome skeletons in some of the world's most secretive religious establishments. Photo: Albertus in the church of St George in Burgrain, Germany. Incredibly, some of the skeletons, which took up to five years to decorate, were even found hidden away in lock-ups and containers. (Photo by Paul Koudounaris/BNPS)

Children surround a man, left, that fell down while walking on a street suspected of having contracted the Ebola virus in the city of Monrovia, Liberia, Tuesday, August 19, 2014. The World Health Organization says the outbreak has killed more than 1,200 people, while authorities struggle to contain its spread and treat the sick. (Photo by Abbas Dulleh/AP Photo)

A resident looks into a newly-built giant trash can, partially buried underground, next to a street in Taiyuan, Shanxi province November 6, 2014. The trash can, which has a diameter of 1.9 meters and a depth of 2.8 meters, could contain approximately 10 cubic metres of garbage. It was built to replace an open-air garbage dump site, local media reported. (Photo by Reuters/Stringer)

An Afghan woman fills containers with water near her temporary shelter at an internally displaced person's (IDP) camp on the outskirts of Herat, Afghanistan, January 21, 2015. Dozens of families are living in temporary shelters even in harsh winters and most depend on aid distributions by the United Nations High Commissioner for Refugees (UNHCR). (Photo by Jalil Rezayee/EPA)

A policewoman wipes her tears as she stands in front of metal caskets containing the bodies of Special Action Force (SAF) police who were killed in Sunday's clash with Muslim rebels, at Villamor Air Base in Pasay city, metro Manila January 29, 2015. Philippine President Benigno Aquino urged legislators on Wednesday not to abandon a plan for autonomy for Muslims to end a decades-old insurgency after the clash in which dozens of people were killed, saying doing so would dash hopes for peace. (Photo by Romeo Ranoco/Reuters)

A makeshift cart with containers is seen at a suspected drug tunnel under construction during a media tour by Mexican Army in Tijuana April 7, 2015. Mexican soldiers foiled the construction of a suspected drug tunnel underneath a house near the U.S. border, arresting nine people and impounding a truck used to clear debris, the Army said on Tuesday. Wired with lights, the tunnel was being built next to the Tijuana border crossing, south of San Diego, California, and near a Mexican air force installation as well as a regional federal police facility. (Photo by Reuters/Stringer)

A kitten singed whiskers that survived the McKinney Fire hides in rocks in the Klamath National Forest northwest of Yreka, California, on July 31, 2022. The largest fire in California this year is forcing thousands of people to evacuate as it destroys homes and rips through the state's dry terrain, whipped up by strong winds and lightning storms. The McKinney Fire was zero percent contained, CalFire said, spreading more than 51,000 acres near the city of Yreka. (Photo by David McNew/AFP Photo)