History:
(Black Goliath#5 (fb) - BTS) - The planet Kirgar was once a mighty imperial state, rivaling the Rigellians and the Kree. However the great empire collapsed millions of cycles (years?) ago, and the race was believed to have become extinct. One of the last warlords of Kirgar had a gigantic fortress to protect his belongings from those who would steal them. When that warlord died, he left the powerful robot Mortag to protect the stronghold. Mortag apparently remained in the lower levels of the stronghold for an untold period of time.

(Black Goliath#5) - After being hit by the beam from Stilt-Man's Z-Ray, the human adventurer Black Goliath and his friends Celia and Keith Jackson were transported to the desolate world of Kirgar. The trio was soon befriended by the A'Askvarii explorer Derath, who was also stranded there after his spacecraft had crashed. With Derath as their guide, the four made their way to the stronghold, in search of a means to help them return to their respective worlds. Derath adapted some of the technology within the stronghold and constructed a dimensional transporter, which would take them all back to Earth.

   But the group's presence in the stronghold had activated Mortag, who silently stalked the relaxing Goliath and Celia. Mortag raised his axe and would have likely slain both of them had not Derath seen Mortag's approach; Derath heroically leaped in the path of the axe, pushed the two aside, and died in their place.

   Black Goliath grappled with Mortag, but seemed to be outmatched in both strength and fighting skill. However, Celia fired upon Mortag with Derath's blaster, which momentarily stunned him and allowed Black Goliath to gain the upper hand. Black Goliath punched Mortag into a power board, which exploded, leaving Mortag in inert pieces. After learning that Derath's killer was a robot, Black Goliath angrily hurled the remains of Mortag's head aside.

An immense structure on the desolate world of Kirgar, it appeared to be a pyramid, but its base was actually a mile below on the original floor of the desert-world -- it had likely been buried over the centuries by the planet's frequent sandstorms.

A million years earlier, it had once been the fortress of the last warlord of Kirgar. Its interior included a vast scientific research center, with machinery and instrumentation that still functioned perfectly, even after eons of inactivity. The installation was powered by fusion reactors in the planet's core.

The stronghold was guarded by the giant robot Mortag, who was activated when he sensed the presence of intruders.

(Comment: The extinct Kirgarians were never depicted, but judging by that ladder and the scale of the instrumentation (see second image), I'd guess that they were probably standard-sized humanoids.)

--Black Goliath#5