Tomb World

The Necron Sigil used to mark their ruins on various Tomb Worlds

A Tomb World is one of the worlds across the Milky Way Galaxy where the ancient and terrible xenos known as the Necrons chose to go into hibernation over 60 million standard years ago, deep beneath its surface in their specially prepared catacombs and tombs. Many Tomb Worlds are now settled planets of the Imperium of Man and their status as a Necron Tomb World remains unknown until the Necrons beneath its surface begin to awaken, much to the detriment of all life on the world. An unknown number of these planets exist across the galaxy in the 41st Millennium. Some Tomb Worlds were once the settled worlds of the ancient Necrontyr species that eventually became the cybernetic Necrons after their enslavement by the C'tan, and Necrontyr ruins are sometimes found on or beneath the surfaces of such worlds. Many Necron Tomb Worlds are now Dead Worlds, largely lifeless and barren deserts. Whether this is a result of the Necrons having cleansed all life from the world millions of years before during one of ther foul "red harvests" or whether such climates were the preferred homeworlds of the Necrontyr civilisation, is unknown. Many of these worlds are often the sites of archeological expeditions carried out by Adeptus Mechanicus Explorator teams looking to uncover ancient xenos or STC technologies or Rogue Trader expeditions hoping to turn a profit from what they discover. Many of these exploratory teams are never heard from again once they begin to explore Necrontyr ruins that inevitably lead them to the tombs of the dormant Necrons that lie beneath the sands.

The Necrons' underground tombs are generally quite large and cavernous, containing repair facillities that are manned by Tomb Spyder robots that repair the Necrons that were critically damaged in recent battles. They have stasis units, in which the dormant Necrons hibernate. They also usually have a large room in which either the Necron Lord that commands the Tomb World (occasionally called a Platinum Lord or a Tomb Lord) or one of the four remaining C`tan sleep in a massive, ornate, black stone sarcophagus.

The list of known Tomb Worlds in the Imperium is delineated below:

Planet name	Segmentum	Sector	Subsector	System	Population	Affiliation
Damnos	Ultima Segmentum	Unknown	Unknown	Unknown	Unknown	Necron
Pavonis	Ultima Segmentum	Unknown	Unknown	Pavonis System	300,000,000	Imperium of Man
Cthelmax	Ultima Segmentum	Unknown	Unknown	Unknown	None	Imperium of Man
Kronus	Ultima Segmentum	Lithesh Sector	Unknown	Unknown	Unknown	Imperium of Man Tau Empire
Naogeddon	Ultima Segmentum or Segmentum Obscurus	Unknown	Unknown	Unknown	None	Unknown
Kaurava III	Ultima Segmentum	Lithesh Sector	Unknown	Kaurava System	Unknown	Imperium of Man
Gorkamorka (Imperial name: Angelis)	Ultima Segmentum	Unknown	Unknown	Unknown	Orks	Orks
Rahe's Paradise	Unknown	Unknown	Unknown	Unknown	None (Exterminatus eliminated the population)	Imperium of Man
Lorn V	Ultima Segmentum	Unknown	Unknown	Lorn System	None	Imperium of Man
Selaaca	Segmentum Pacificus	Vieled Region	Unknown	Selaaca System	Human population harvested by Necrons	Necron (formerly Selaacan Empire)
Sanctuary 101	Unknown	Unknown	Unknown	Unknown	Unknown	Imperium of Man
Phaethon IV	Unknown	Unknown	Unknown	Phaethon System	Unknown	Imperium of Man

Sources

• Codex: Necrons (3rd Edition)
• Warhammer 40,000: Dawn of War - Dark Crusade
• Warhammer 40,000: Dawn of War - Soulstorm
• Nightbringer (Novel) by Graham McNeill
• Warhammer 40,000 Rulebook (5th Edition)