backyardhardwaremetaloutdoor
My child has been swinging in our front yard (NC, US) and worn away the grass, revealing this metallic stake (* See photo, note the acorn top for scale*):
I gently tried to pull it up, but it is lodged in pretty well, and I don't want to damage city property it could indicate a gas line or something important. I don't think it is a ground rod (it seems to be stainless steel).
As it is right under her swing I'd like to remove it as it is a safety hazard, but I think I probably shouldn't.
Backflow preventer: The fitting closest to the faucet MUST unscrew CCW.
Looking at your bib at the house siding, its not secured. Use a second wrench on the faucet, torquing in the opposite direction to the wrench on the backflow adapter. This will prevent you from busting the water pipe and REALLY making a mess. Backflow article
Looks like a rain gutter or sump pump outlet. Place a noisy device directed into it and walk around and listen.
You could probably bury the white pipe and just leave the grille exposed, flush with the lawn.
Best Answer
Looks like a run-of-the-mill landscape stake to me. They're used for securing plastic edging, fabric, etc. Could also be a tent peg. It's a horse apiece.
I'd give it a few taps with a hammer to loosen it, then try prying it out with a spade or the hammer with a block under it.