Tyrest

The sky is falling! The sky is falling!

The Manganese Mountains is a remote mountain range somewhere on Cybertron.

Fiction

Marvel Comics continuity

Fortress Maximus and his troops operated out of a cave gouged out of the Manganese Mountains until they got sick of the war and left for Nebulos. Ring of Hate! Some time later, Scorponok's forces raided the abandoned base and found out where the Autobots had gone to. Broken Glass!

Shattered Glass

When the Autobots destroyed Tyrest University, the three Predacons went into hiding in the Manganese Mountains and started honing their hunting skills. The mountains soon became known for being haunted by vicious killers.