It is estimated that there are about 2 million lakes on earth, some are natural lakes formed by volcanic and glacial activities, and some are artificial lakes. Among the many lakes, there are freshwater lakes and saltwater lakes. There are large and small lakes all over the world. Below are the 5 largest lakes in the world.

Although the Caspian Sea is called "sea", it is actually a lake. It is the largest lake in the world, but it contains an ocean basin rather than being entirely on the continental crust. This makes it an ocean lake unlike all other lakes on this list (continental lakes). The Caspian Sea is also the third deepest lake in the world. With an area of 371,000 square kilometers, the Caspian Sea is also the largest saltwater lake in the world. The Caspian Sea is located on the border of Europe and Asia, spanning 5 countries, and it is the lake with the largest number of countries in the world.

Surrounded by Canada and the United States, Lake Superior is the largest of the Great Lakes in North America. Lake Superior is shared by Ontario, Canada to the north, Minnesota, USA to the west, and the Upper Peninsula of Wisconsin and Michigan to the south. The northernmost and westernmost point of the Great Lakes region, Superior has the highest elevation of all five Great Lakes and empties into the St. Mary River.

Lake Victoria is the largest lake in Africa and the largest tropical lake in the world. It is surrounded by Uganda, Kenya and Tanzania. Lake Victoria, named after Queen Victoria, was named by explorer John Hanning Speke, who was the first Englishman to record it. Speke found the source of the Nile during an expedition with Richard Francis Burton in 1858. Lake Victoria's water comes primarily from direct rainfall and thousands of creeks. The Kagera River is the largest river flowing into this lake, and its mouth is located on the west bank of the lake. Lake Victoria is completely drained by the Nile River near Jinja, Uganda, and lies on the lake's northern shore.

Lake Huron is one of the five great lakes in North America. Its north and east are in Ontario, Canada, and the south and west are in Michigan, USA. The lake takes its name from the early French explorers who named it for the Huron people who lived in the area. The Huronian Glacier was named due to evidence collected from the Lake Huron region. The northern part of the lake includes Northern Sound and Georgian Bay. Across the lake to the southwest is Saginaw Bay. The main entrance is the St. Mary River and the main outlet is the St. Clair River.

Lake Michigan is also one of the Great Lakes, slightly smaller than Lake Huron. It is also one of the largest lakes in the world and is entirely within one country (the United States). Chicago and Milwaukee are located on the shores of Lake Michigan. To the east, its basin is connected to that of Lake Huron by the wide Mackinac Strait, making it the same elevation as the easterly, and the two are technically a single lake. Lake Michigan is shared from west to east by the US states of Wisconsin, Illinois, Indiana and Michigan. Ports along the coast include Chicago, Milwaukee, Green Bay, Wisconsin, Gary, Indiana, and Muskegon, Michigan. The word "Michigan" originally referred to the lake itself.