Ancient Waters: 4 of the Oldest Lakes in the World

Written by Jude Speegle
Updated: May 28, 2022
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Our Earth is seventy-one percent covered in water, so it shouldn’t shock many that there are waterways older than the human race. The oldest lakes in the world contain ancient waters far older than we can fathom!

Today we’re examining the oldest lakes in the world. With so many other bodies of water being old, it might shock you to learn that very few lakes are more than even millions of years old. We’ll explore four of the oldest lakes in more detail below!

The Oldest Lakes in the World

Humans evolved around 200,000 years ago, while the oldest known bodies of water range from 30-70 million years old. That’s enough time for many other forms of life to have conquered the world and then withered away. There are only about 20 lakes that are believed to be more than a million years old.

In comparison, the Cretaceous period was only 66 million years ago. So the dinosaurs never drank from these lakes, but closer ancestors than we have in the present day did. There is debate on the accuracy of dating for these water bodies, and one that may have dated to the cretaceous period is slowly building to extinction.

A few of the most ancient waters include:

  • Lake Biwa
  • Lake Baikal
  • Lake Tanganyika
  • Lake Zaysan

Let’s explore exactly how these 4 ancient lakes came to be and what makes each one unique and fascinating.

What Makes an Ancient Lake?

An ancient lake is one that has had water for at least a million years.


With all the water in our world, what constitutes an ancient lake? How can we tell the age of the water?

An ancient lake is one that has held water for, at minimum, one million years. There are only 20 of these ancient lakes known. Most of what we consider ancient lakes have had water for the Quaternary period, which means in the last 2.6 million years. 

This is relevant because that period has a lot to do with the growth and recession of glaciers and large mammals. Glacier withdrawal definitely can contribute to many of these lakes beginning their periods of holding water. Often these ancient lakes still exist thanks to being over a rift zone.

A rift zone is a place where plate tectonics contribute to the depth of the lake, making it harder for it to dry out or fill with dirt. Divergent plates, or plates that are across from one another, form a connection as a valley, then the valley becomes the bottom of the lake. It can constantly be growing deeper over time.

Lake Biwa

Oldest Lake - Lake Biwa

Lake Biwa is the largest freshwater lake in Japan


Japan is the home of Lake Biwa, the largest freshwater lake in the country. Lake Biwa is only thirty miles out of Osaka and is the perfect getaway for a day trip. It is around four or six million years old and is the result of being over a rift zone. 

This lake is home to more than 1,000 different animal species and is huge for waterbird migration, having more than 5,000 travel to it over the year. Some fish that can be found include:

The freshwater that fills this lake is a beautiful, rich blue and is part of the reservoir for water for neighboring cities. It’s a stunning view at sunset, reflecting the pink hues and showing off bordering mountains. 

Lake Biwa also supports a strong pearl industry due to its staggering amount of freshwater mussels that are endemic to the area. This means certain mussels can only be found in these waters.

258 square miles long with a depth of 341 feet, Lake Biwa doesn’t stand out much in size or depth compared to the other lakes on this list, but it provides for the community around it in a rich way. It serves as a reservoir for the cities of Kyōto and Ōtsu and is a valuable resource for nearby textile industries. Lake Biwa eventually flows into the Seto Inland Sea.

Its name supposedly comes from its similarities to an instrument known as the biwa, and it was first named in writing around the 14th century.

Lake Baikal

Lake Baikal is the largest and deepest freshwater lake in the world.

©Nikitin Victor/

Lake Baikal is often cited as the oldest lake in the world because it can be definitively dated. It is not based on hypotheticals the way the science for Lake Zaysan (the oldest) is. This lake also happens to be both the largest and the deepest freshwater lake in the world.

This lake is 25 million years old, with perfectly clear waters that sink into its depths. Clearwater bodies form because of a sound filtration system and lack of sediment in the water. This lowers its acidity and produces tinged clear water. 

With clear blue waters and a frozen center, Lake Baikal is a three-day adventure along the Trans-Siberian Railway, starting in Moscow, Russia. It is not for the faint of heart and can be a grueling journey.

Lake Baikal reaches a span of 12,248 miles with a depth of 2442 feet. With seventy-one percent of the world covered in water, this lake holds a whopping twenty-three percent of that water. There are species of animals that can only be found in this lake and the surrounding areas.

Glacier runoff originally formed this lake, which is part of what helps keep it crystal clear. Many bodies of water made from glacier melt are clear in the same way.

Lake Tanganyika

Lake Tanganyika is home to many species, including the Nile Crocodiles.

©Naoki Kakuta/

Compared to Lake Baikal, Lake Tanganyika ranks second in many aspects. It is the second-largest and second deepest freshwater lake in the world. It does come in first place as being the longest lake of its kind at 418 miles in straight length.

Parts of this lake are anoxic, which means the water lacks oxygen. This is because it has fossilized water in some deep sections, water so old it no longer holds oxygen. Some areas have limited animals because they cannot sustain fish.

This lake is also unique because it is spread across four countries: Burundi, the Democratic Republic of the Congo, Tanzania, and Zambia

Since Lake Tanganyika borders so many territories, a wide variety of animals and marine life call this lake home. Some animals are:

The waters travel outward in rivers and eventually empty into oceans. Locals subsist on fishing, and it supports more than 800 fisheries in the area. 

Depending on where the border is, the scenery changes slightly. Some beaches are made of soft white sand, while oil palms or rice fields border others.

Lake Zaysan

Oldest Lakes - Lake Zaysan

Lake Zaysan is the oldest lake in the world, but it holds that title controversially because the science is not definitive.

©Maxim Petrichuk/

When it comes to the exact dating of Lake Zaysan, there is a lot of debate about its precise age. It is believed that the basin, the bowl of the lake which contains the water, has never dried. This means that based on scientific evidence, it could have first formed around 60-70 million years ago.

The Cretaceous period ended sometime in that little gap, so it is quite possible that dinosaurs did drink from the water, but there is no unshakeable truth. The next lake on the list is often cited as the oldest lake is known globally, but that is only because it gets a lot of attention for other reasons.

This lake is found in a small hollow between the Altai and Tarbagatai Mountains, located in Kazakstan. This lake actively holds many species of fish, including:

This is a natural freshwater lake known to be frozen from November to April. Fishing is integral to the local societies and is the main profit for their communities. It extended around 700 miles with a depth of 49 feet and is a dark blue-green in color.

Due to a dam built in the 1950s, there is a chance that Lake Zaysan is in its final stages and headed toward becoming extinct.

The photo featured at the top of this post is © beeboys/

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About the Author

Jude is a writer both by trade and by heart. They have been writing since a very young age and have eight years of professional writing experience. Passionate about animals, Jude has three birds and three cats.

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