Lake Peipus the town. Near Kallaste, there is one of the largest surfacings of Devonian sandstone with a length of and a maximum height of , as well as several caves and one of the largest colonies of swallows in Estonia. Lake Peipus Lake Peipus (; ; ) is the largest transboundary lake in Europe, lies on the border between Estonia and Russia. The lake is the fifth-largest in Europe after Lake Ladoga and Lake Onega (in Russia north of St. Petersburg), Lake Vänern (in Sweden), and Lake Saimaa (in Finland). Lake Peipus represents a remnant of a body of water which
Lake Chad Bodélé depressions. The climate is dry most of the year, with moderate rainfall from July through September. Lake Chad gave its name to the country of Chad. The name "Chad" is a local word meaning "large expanse of water", in other words, a "lake". Lake Chad is the remnant of a former inland sea, paleolake Mega-Chad. At its largest, sometime before 5000 BC, Lake Mega-Chad was the largest of four Saharan paleolakes, and is estimated to have covered an area of , larger than the Caspian Sea is today, and may have extended as far northeast as within of Faya-Largeau.