Lusitania is the Nepper homeworld, which was where they developed after being brought from Claes as microorganisms. The rees, who evolved long before the neppers gained intelligence, made several attempts to colonize Lusitania, but the Neppers evolved quickly, and with ther newfound intelligence, they defended their homeland. At the same time, they found out that rees taste great, and to this day, they're still after them in hopes of roast ree for dinner.
Lusitania is a topograhically varied planet composed mostly of mountains and desert landscapes. The Neppers usually stick to the mountains and stay out of the deserts.
When cities became too overcrowded on Lusitania, the Neppers demolished them all in favor of tall arcologies that take up less space on the planet.
Lusitania has no moons.
The planet orbits a binary star system. Two suns, one of which is much larger than the other, can be seen from the planet. These suns make the planet very hot year-round.