At 4145 miles from your furthest extremity to the Mediterranean Sea, you outdo the Amazon to become the world's longest river. The piranhas hate you.
Beneath you lies an underground river with six times your volume. You kept this remarkably quiet for several thousand years. In fact, you're full of mystery; your source wasn't discovered until 1862. You're also full of water. And crocodiles. And nuclear pharaoh machines that run on light and can see through time.