Lake Baikal, Russia

Lake Baikal tops the list of the world’s 10 deepest lakes. It is the largest lake in Russia and the world in terms of volume. Lake Baikal has a maximum depth of 1,642 m and is located in southern Siberia. It is considered the biggest natural freshwater reservoir on the planet. Its volume exceeds the freshwater resources of all lakes in the United States, containing around 20% of the world's fresh surface water. Above all else, it is an ancient lake with a unique ecosystem that has existed for 25-35 million years and serves as home to more than 1,700 species of plants and animals. Baikal is also a UNESCO World Heritage site.

Lake Tanganyika, Africa

Lake Tanganyika is the second largest lake on our list. It is the deepest lake in Africa and the world with a maximum depth of 1,471 m. It is very long (673 km) and flows in four African states – Tanzania, Congo, Burundi, and Zambia. The lake was discovered in 1858 by John Speke and Richard Burton, British explorers. It is located in the deepest tectonic basin in Africa. Numerous small rivers and streams flow into the lake with one major outflow – the Lakuga River. Lake Tanganyika is home to crocodiles, hippos, waterfowl, and several unique fish species.

Lake Vostok, Antarctica

Lake Vostok takes third place in the ranking. It is the largest subglacial lake on the planet. The surface of the lake under the ice is 4 km. This unique 1200 m-deep water reservoir is located in Antarctica, beneath Russia's Vostok Station, and is named after it. On the lake, discovered in 1996, drilling of the ice shell continued for 20 years. In February 2012, Russian scientists reached the upper surface of the water. Exploration of the reservoir may unveil the mystery about ancient life forms that existed millions of years ago.

Caspian Sea, Russia

The Caspian Sea is the world’s largest endorheic basin, containing saltwater and having a maximum depth of 1,025 m. It is also considered a full-fledged sea because of the oceanic crust layer at its core. Owing to the unique location of the sea (between Europe and Asia), its waters wash the shores of five countries - Russia, Iran, Kazakhstan, Azerbaijan, and Turkmenistan. Over 130 rivers provide inflow to the Caspian with the Volga River being the largest. The Caspian Sea has very abundant fauna. It is home to the Caspian seal and several species of sturgeons. This inland body of water is a rich source of energy resources as well. The total cost of oil and gas produced here totals $12 trillion.

San Martín, South America

San Martin, also known as O’Higgins, is the world’s fifth deepest lake. This water reservoir is 836 m deep. The lake is located in Patagonia, on the border between Argentina and Chile, and has an elevation of 250 m above sea level. Notably, the lake is known as San Martin in Argentine and as O’Higgins in Chile. Both names come from independence heroes José de San Martín of Argentina and Bernardo O'Higgins of Chile. The lake is mainly fed by the Mayer River and small glacial streams. San Martin has a milky light-blue color that comes from rock flour suspended in its waters. It falls into the lake with melted water from glaciers and settles at its bottom.

Lake Malawi, Eastern Africa

Lake Malawi, also known as Lake Nyasa, takes sixth place in our ranking. It has a maximum depth of 706 m. The lake is located at the southern tip of the East African Rift system, between Malawi, Mozambique, and Tanzania. The tropical waters of Lake Malawi are home to more unique species of fish than any other lake on the planet. According to scientists, it has decreased by 100 m in depth in the past 100,000 years. This is caused by surface evaporation (up to 80%) and the Shire, the southern outflow of Lake Malawi.

Issyk-Kul, Middle East

Issyk-Kul is a 702 m-deep lake in the Northern Tian Shan mountains in Eastern Kyrgyzstan. It is the seventh-largest endorheic basin. In the Kyrgyz language, Issyk-Kul means "warm lake". The lake got its name owing to its never-freezing salt waters. Some fascinating legends are associated with Issyk-Kul. One of these legends says that an ancient Armenian monastery with the relics of St. Matthew is buried under the surface of the lake. These myths are not without foundation: traces of an ancient civilization that existed 2,500 years ago were discovered at the bottom of Issyk-Kul in 2006.

Great Slave Lake, Canada and United States

Great Slave Lake is the world’s eighth deepest lake. It has a maximum depth of 614 m. The lake remains frozen for eight months a year and has an incredibly thick layer of ice in winter. This ice is believed to support the weight of the truck. In the 1930s, gold was discovered here, marking the beginning of the so-called gold fever. Such an amazing discovery led to the establishment of the city of Yellowknife on the shore of the lake.

Crater Lake, United States

Crater Lake with a maximum depth of 594 m takes ninth place in the ranking. It is the main feature of Crater Lake National Park in Oregon. Crater Lake was formed by the collapse of the volcano Mount Mazama more than 7,000 years ago. The lake is famous for its water clarity and deep blue color owing to the melting of snow. Crater Lake is also known for the Old Man of the Lake, a huge log that has been standing vertically there for more than 100 years.

Lake Matano, Indonesia

Lake Matano is the world’s tenth deepest lake. This water basin of tectonic origin is located in South Sulawesi, Indonesia. The 590 m-deep lake is the key source of fresh water in the country. It is famous for its crystal clear waters that serve as home to rare species of plants, fish, and crustaceans. Nickel ore deposits have been discovered on the shores of Lake Matano.