Crimson Monolith
Rising from the eastern dunes, the Crimson Monolith is a blood-red needle-like structure made of an unknown stone. It is smooth and warm to the touch, and some claim it pulses like a living thing. It's base is about 15 feet around, tapering to a point some 40 feet into the air. It has no seams, doors or windows, and no apparent function.
Some travelers claim that on nights when the twin moons are high in the sky, strange creatures simply step out of the monolith to explore the nearby dunes. No doors ever appear to announce their presence. When the moonlight begins to wane, the beings step back into the monolith just as mysteriously. Accounts of these beings vary wildly. Some stories paint these visitors as extra-planar travelers, some as ghosts from an ancient age, and some as denizens traveling from remote and hidden parts of Athas. The truth remains a puzzle, very much like the Monolith itself.