Tarp Fence Falling Right Green
While not as sturdy as solid concrete, iron constructions have high structural integrity, requiring fewer support pillars.
Harvest drops
Iron× 10
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Scrap Metal Pile (60% of the time) where it lands.
Where to find (28 POIs)
Navezgane Athletics Complex (tier 5), Ostrich Hotel (tier 5), Doominium Tower (tier 4), Downtown Marketplace (tier 4), Green Hill (tier 4), Housing Development (tier 4), Atlas Metal Company (tier 3), Greg's Motel (tier 3), The Serrano Residence (tier 3), Bell Lake (tier 2), Congregation of Blind Faith (tier 2), Federal Appliance (tier 2), Sweet Sweet Honey Pot Farms (tier 2), Crazy Billy's Used Cars (tier 1), Oskar's Dumpster (tier 1), The Dead Rooster (tier 1), The Roland Residence (tier 1), The Smokehouse (tier 1), Bruno's Boulevard, County Stockpile, Deepwell Shack, Downtown Construction Site, Industrial Construction Site #10, Junkin, Leyline Electric Depot, Shady Dawgs, Trader Bob, Urban Style Shops.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.