Steel Pillar (Primitive Plus)

The Steel Pillar is a Structure in the Primitive+-DLC of ARK: Survival Evolved.

Steel pillars are a direct upgrade to concrete pillars. They can only be damaged by explosives, and they take considerably less damage from the explosives than concrete pillars do.

Construction
The Steel Pillar can be placed on even or slightly uneven ground, or on the top or bottom of foundations, ceilings, or other pillars. Once the first Pillar is placed, subsequent pillars can snap into place on the top or bottom of the first one, provided there is adequate room to do so.

A pillar or series of pillars with the bottom touching the ground and a ceiling on top will function as a foundation, providing support and allowing structures to be built on top of it.