Erta Ale volcano

The Erta Ale volcano is a mountain in the Danakil Desert. The locals know it as "The Gateway to Hell".

Megatron's Law
Annoyed at his army's constant losses against the Autobots, Megatron took over a cavern in the side of the volcano and filled it with cages so he could hold deathmatches for the Vehicons in an attempt to strengthen his army. The volcano's natural magnetic pull prevented the combatants from transforming, leaving it a matter of brawn, just the way Megatron liked it.