Before becoming Dr. Hell's base, the ruins on the island featured rooms filled with giant robots. After Dr. Hell made his base; he added a command room to observe events that unfolded, a Mechanical Beast manufacturing plant for building the Mechanical Beasts, a hanger for the Mechanical Beasts, and executive room for training the combatants. The beaches on the island are used for testing the Mechanical Beasts before they are sent out into battle. A hangar for the Gool also exists.
On an expedition, a team led by Juzo Kabuto discovered the giant machines. One of the scientists, now calling himself Dr. Hell managed to rebuild some of the giant soldiers and had them attack the other scientists in his first step towards world domination (Juzo survived). While Dr. Hell had many fortresses, he and his lieutenants were based mainly on Bardos as it was where Dr. Hell developed a majority of his Mechanical Beasts.
After a while, the Mazinger team attacked Bardos to defeat Dr. Hell. While they succeeded, a new more powerful threat came from below, the Mycenae Empire itself. With Dr. Hell's defeat, the Mycenae Empire used the island as one of their bases.
- Bardos appears to be based on the real-life Aegean Sea island, Rhodes.
- The Mechanical Beasts found on Bardos is a reference to the Greek legend of Talos.