At the place where the Nile flows closest to the Red Sea, a trade route crosses the desert. Since ancient times it connects Luxor, the former royal city of Thebes, to the shore. Today, a natural paradise lies at its source: The bay of El Quseir el Quadim. The most bio-diverse coral reef in the Red Sea has overgrown the walls of the ancient port and buried under the sediments lies the former harbour of the pharaohs, forgotten, at the edge of the Egyptian desert. Why some inhabitants of the oceans display fluorescence and others do not, is the subject of investigation, but this is by no means the only secret of the bay of El Quseir el Quadim.