Or some sort of big "No Jedi allowed!" sign, I'm sure.
Passing through this smaller blast hatch delivers you out onto a series of rickety catwalks that line the walls of a hollowed cavernous ovular chamber within the cliff. The roughness but shaped nature of the chamber's walls tells you of its origin- unnatural, man-made, likely with ancient equipment that lacked the sophistication of plasma drills.
Below, grooves in the cavern floor compose "streets" separating squat structures, building hewn from the stone. Thousands of people hustle about, but you cannot tell what purpose the buildings actually serve. Some have additional man-made structures extending the stone dwellings upward, forming short towers.
Opposite of you, at the very far end of the chamber, you see a more advanced complex, a metal quarter sphere built into the cavern wall. The top composes a flat deck area, and the upper levels sport large open balconies. The lower levels are darker and denser and armored. Catwalks feed into these lower levels.
But by far the most impressive thing is some sort of large generator thrumming along on the right side of the room. Perched atop it in a containment field sits what appears to be an artificial sun, radiating heat and light into the cavern. The containment field shifts, brightening and dimming as the star within it scintillates calmly, so as not to blind all who look upon it.
You have never seen anything quite like it.