These two lakes have two completely different fates. One of them is situated in Asia, in Eastern Siberia, the other in the South-East part of the African continent. Baikal and Tanganyika “compete” with each other in many morphological indicators: size, water volume, length of the coastline, depth, and others. However, the main difference is the fact that Baikal water is suitable for drinking, while the water of Tanganyika is not suitable for drinking at all. We decided to graphically compare the most important indicators of these two oldest lakes.