Barsoom (better known to Earthmen as Mars, by the inhabitants of Jupiter as Garobus) is the fourth planet in the Solar System, and the main setting of Edgar Rice Burroughs’ Martian novels.

It is orbited by the moons Thuria (Phobos) and Cluros (Deimos). In the distant past, it bore five oceans, the largest and mightiest of them Throxeus. Today these oceans are all but dried out, and the planet now has very little water.  Most Barsoomians believe there is a body of water in the south called Korus.