Geologically, this limestone fractures in relatively predictable ways, producing large slabs that can be worked with stone tools into more refined shapes.

The T-profile of the pillars, which gives the site much of its visual distinctiveness, appears to have been achieved through a combination of rough quarrying to free the basic form from the bedrock and then careful grinding and pecking to refine the surface.

The T-bar at the top — the horizontal extension that caps the narrower vertical shaft — is a consistent feature of the Göbekli Tepe pillar type that appears to have been intentionally designed rather than simply the product of convenient stone fracturing.

In the stone-working area to the northwest of the main excavated enclosures, a broken and abandoned pillar offers the most direct evidence of the quarrying process.