Knowledge for you

Lake Baikal
The oldest and deepest lake on earth located in Russia.

All told, fresh water lakes make up just 0.007% of the total amount of water on Earth, but comprise the overwhelming majority of liquid fresh water on our surface. Most of Earth's lakes are relatively young, less than 18,000 years old and formed during the end of the last ice age. Only 20 lakes, worldwide, are ancient: more than 1 million years old. But Lake Baikal is not only Earth's oldest lake, at 25-30 million years of age, but it's also the largest.

Although practically all of Earth's human population lives on dry land, our surface is 71% covered by water. Of that water, almost all of it is in the oceans, with just 2.5% of it in the form of fresh, rather than salt, water. Most of Earth's fresh water is in glaciers, ice caps, and permafrost, and water and ice beneath the surface. Most of the rest, as you might expect, is in the large reservoirs of liquid water on our land masses: Earth's lakes.

source: forbes and wiki.