Undergrid

The Undergrid is a location from the Generation 1 continuity family.

The Undergrid is a location far beneath Iacon on Cybertron.

Fiction

IDW Generation 1 comics

During Zeta Prime's rule, the Matrix of Leadership was hidden in an ancient vault in a part of the Undergrid connected to the Citadel. After he was betrayed by Megatron, a badly wounded Orion Pax was thrown into the Undergrid where he encountered the Matrix that turned him into Optimus Prime. Transformation