Jan-Ja

We're not sure whether to make a joke about "smoking Jan-Ja" or "Jan-Ja Binks" so... Hey, look! The Autobots are covered in Electrum!

Jan-Ja is the location of a historically significant battle in which Optimus Prime refused to surrender to superior Decepticon forces and instead led a charge to victory.

Fiction

Marvel The Transformers comics

Not long before Optimus Prime and his crew launched from Cybertron in the Ark to clear threating asteroids, he was defending the Jan-Ja in what seemed to be a doomed attempt to keep the Decepticons from taking Iacon. Mattock urged Prime to surrender. Prime told him to get out the white flag. Relieved, Mattock unfurled it only to be shocked when Prime ordered him to bind his wound with it. With that, Prime ordered a charge, which was apparently successful in protecting Iacon. Surrender!

3H comics

The Chronarchitect, when trying to temporally compose himself, was at Jan-Ja during Optimus Prime's charge. He saw the 'bot who would be Prime pick up his fallen Monark's banner and charge. Covenant

Notes

• Other Autobots present at the battle include: Jazz, Ironhide, Prowl, and Wheeljack.
• The time of the battle was given as 4 million years ago ± a few thousand years.
• The location of the battle was not named in the comic itself, only later being revealed in "Covenant".
• It's not clear who or what a Monark is in the context of Transformers, but he sure sounds like he must be important.