In what fictional work does the planet Cybertron feature?
Cybertron
Cybertron's upper layers seem to have a lot of interlocking hexagonal shapes, and several battles near the end of the war took place there. Sentinel Prime used these geographical features to his advantage when he attempted to escape Cybertron aboard the Ark. Later on, Sentinel Prime attempted to teleport Cybertron via the space bridge-forming pillars from his ship, the Ark in order to acquire Earth's resources to re-energize Cybertron. However, Bumblebee destroyed the master pillar and Cybertron collapsed as it was going through, presumably destroying Cybertron forever.