10 most difficult lakes riddles

In Antarctica we can find the Erebus high volcano at nearly 4 km, the Don Juan pond with a salinity of 44.2%, and the desert of the McMurdo Valleys. Lake Vostok with an oxygen content 5 times more than the average, however, is hidden under a 4 km layer of glacier.

Minnesota is a state in the midwestern and northern regions of the United States. Minnesota was admitted as the 32nd U.S. state on May 11, 1858, created from the eastern half of the Minnesota Territory. The state has a large number of lakes, and is known by the slogan "Land of 10,000 Lakes".

The Boiling Lake is situated in the Morne Trois Pitons National Park, Dominica's World Heritage site. It is the second-largest hot lake in the world after the Frying Pan Lake in New Zealand. Its temperature range is from 180 to 197 °F (82–92 °C) along the edges, but at the centre it is actively boiling.

Lake Taupo is a lake in the North Island of New Zealand. It is in the caldera of the Taupo Volcano. With a surface area of 616 square kilometres (238 sq mi), it is the largest lake by surface area in New Zealand.

The Jellyfish Lake is a marine lake located on the Eil Malk island in Palau. It is filled with millions of golden jellyfish, migrating across the lake every day following the arc of the sun. The lake is stratified into two layers, an oxygenated upper layer and a lower anoxic layer, hence scuba diving is forbidden so the two wouldn't mix. But snorkelling is allowed and a very popular activity for tourists in Palau.

Lake Balkhash is the 13th largest lake in the world. The lake is divided by a strait into two distinct parts. The western is a fresh water half, while the eastern half is saline.

Niagara River flows from Lake Erie to Lake Ontario.

The gradient between The Great Lakes is generally very shallow. However, the descent between Erie and Ontario is greater than between any of the others, and includes the spectacular Niagara Falls, 51m high.

The Caspian Sea, fed by freshwater (sweet) rivers, mainly Volga (80%) and Ural in the north, is freshwater, while it's deeper, warmer and saline (1.2%) in the south. The salinity of Garabogazköl, shallow eastern bay is 35%!

The island has an area of 2,766 km2 (1,068 sq mi), making it the 174th largest island in the world and Canada's 31st largest island. Manitoulin Island itself has 108 freshwater lakes, some of which have their own islands; in turn several of these "islands within islands" have their own ponds. Lake Manitou, at 104 km2 (40 sq mi), is the largest island in a freshwater lake in the world, and Treasure Island in Lake Mindemoya is the largest island in a lake on an island in a lake in the world.