The Red Sea is the saltiest sea of all the seas that connect to the ocean without even one river meeting the sea.

Water of the Red Sea isn't red. The water is blue-green, yet it's called the Red Sea.

Why?

The Red Sea's name is a direct translation of its ancient Greek name, Erythra Thalassa. However, only European languages include any mention of "red."

In Hebrew it is called Yam Suph, or Sea of Reeds, most likely due to the reeds of the Gulf of Suez, and in Egypt it is called "Green Space."

A popular theory about the origins of the Red Sea's name is that it contains a cyanobacteria called Trichodesmium erythraeum, which turns the normally blue-green water to a reddish-brown.