What lake has both salt water and fresh water?

Answer 1

All hypersaline lakes contain a mix of both fresh- and saltwater; it is their excess of the latter that classifies them as "hypersaline," which, by definition, means they have a higher salt content than natural seawater (and certainly higher salt content than a freshwater lake).

Like the ocean, these lakes are generally fed by freshwater sources. Environmental and geographic factors are the main contributors to their hypersalinity. Normal lakes, unlike seas and other coastal waters, are landlocked and typically fed and drained by a freshwater river or stream. Hypersaline lakes, however, are often also terminal lakes, meaning they have no outlet and never flow to the sea.

Both the Great Salt Lake near Salt Lake City, Utah and the Dead Sea on the border between Jordan and Isreal are two of the better known hypersaline terminal lakes on Earth.

Answer 2

an estuary?

Its the Lake Balkhash in Kazakhstan.

Answer 3

Lake Balkhash