Lesser Magellanic Cloud
The LMC is cleaned out, denuded of naturally-occurring tachyon vesicles. The cloud shows evidence of at least three native galactic civilizations; the last apparently mined all of the Cloud's vesicles and then fell soon afterward.
Unknown to Humans, both Magellanic Clouds are under the domination of the Gergathan. Since c. 10 million BCE, both galaxies are virtually devoid of intelligent life. The only exceptions (outside Human settlements) are a few well-hidden teleportation facilities on bases maintained by the Gergathan.