Phaester Osiris

Phaester Osiris is the home planet of the Osirians. Roughly 7,000 years ago, Phaester Osiris was ruled by Horus and Sutekh. When Sutekh started his reign of destruction, Phaester Osiris was one of the targets. Only Horus and 740 other Osirians survived the destruction of their home-world. (DW: Pyramids of Mars)

Especially tall pyramids could be found on the planet. (MA: The Dark Path)