Xuthal is an ancient city built over an oasis in the southern deserts of Stygia. Xuthal was constructed by an ancient civilization from the east. The entire city is actually a single great palace, with buildings and closely connected walls within itself.

The inhabitants of Xuthal maintain a highly-advanced culture and technology. However, their society has become decadent and stagnant over time. Most of the time they lay a deep sleep induced by the Black Lotus. In time, their dream-life has become important and real as their waking life.

The inhabitants of Xuthal grow the black lotus inside certain pits within their city. Through the ages, they had cultivated it, until, instead of death, its juice induced dreams. In these dreams they spend most of their life. Their waking lives are vague, erratic, and without plan. They dream, woke, drink, love, eat, and dream again, seldom finishing anything they began.

The inhabitants of Xuthal are superb scientists and manufacture their own food out of the primal elements. Their ancestors are mental giants, who built Xuthal in the desert, and though the race became slaves to their curious passions, some of their wonderful knowledge still remains during the time of the Hyborian Age. For example, they created lights which were in fact jewels fused with radium. Rubbing them one way made them glow, while rubbing them again the opposite way extinguished them.

Xuthal is held in thrall by the demon-god Thog, who prey upon the inhabitants of Xuthal. Thog dwells within a sunken dome near the centre of the city, where it's said he has always lurked. The people of Xuthal worshiped him, despite his predations. However, Thog's actual presence could often induce terror in his worshipers.