This was the Cobra base during the second season, first seen in "Arise, Serpentor, Arise." when a squad lead by Beachhead arrive to rescue Sgt. Slaughter, who was captured by Dr. Mindbender to provide DNA for Serpentor, which he failed to do.
It was once broken into by a creature connected to Destro's clan, which Cobra Commander freed.
Some episodes showed smaller versions of the base.
The Terror Drome would later be blown up when a mission to determine the fate of Roadblock's unit was changed on the spot when Sgt. Slaughter and his four man team overheard a second plan to steal the BET, then rescue one team member in the animated film.