The Red Planet
Barsoom - the dying world known to Earthmen as Mars. A planet of ancient sea beds, crumbling cities, and warring races fighting for survival under twin moons.
The Great Cities
- Helium - Twin cities of Greater and Lesser Helium, home of the red Martians
- Zodanga - The predatory city-state
- Thark - Domain of the green Martian hordes
The Races of Barsoom
Red Martians: The dominant civilized race, skilled in science and warfare.
Green Martians: Six-limbed giants, fearsome warriors of the dead sea bottoms.
White Apes: Savage beasts haunting the ancient ruins.