Baal
Baal is a deserty Death World famous for being the home of the Blood Angels, the most badass vampires in history.
The Blood Angels Primarch Sanguinius, fell upon Baal Secundus after he and his brother Primarchs were scattered across the galaxy by the machinations of the Chaos Gods.
Baal has two moons, Baal Primus and Baal Secundus. Apparently, the moons were damn close to paradise worlds, but the the Age of Strife slightly altered that. The moons' populations now spend their time evolving out of the stone age.
The entire planet is a radioactive wasteland.
Oh and the Tyranids are coming to eat it.