You know my theory about the reef being the bed of an old lake, well this bears it out.

Dr. Cooper said that studies of evolution in the very old lakes promised to be particularly interesting.

That is a military barracks down by that little old lake there.

This 400 year old lake is spread in an area of 1 square kilometre.

It is also among the clearest of all lakes, and thought to be the world's oldest lake at 25 million years.

Since its completion in 1937, wet season flooding around the market has remained a problem and is vestigial evidence of the old lake.

Drumlins north of that line were islands in the old, larger lake.

It is one of the oldest radiocarbon-dated lakes in Africa.

As a result, a new Southern Sea was dug to the south of the old lake.

This area indicates the existence of an old lake, today covered by sediment.