Building blocks
Concrete Pillar 1m Destroyed
A cobblestone block with 500 hit points.
Harvest drops
Small Stone× 16
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Destroyed Stone (75% of the time) where it lands.
Where to find (1 POIs)
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.