Idea what this is?

I’ve never seen this before. I have a clue what it may be, but not positive. House was on a slab with gas heat/hot h20. Neighboring houses had same thing.

What was directly above that (outside and inside) between the garage door and entry door?

sewer cleanout?

fill pipe for under ground oil or propane storage?

sanitary sewer drain vent

builders here like to put them in the middle of the front entry walkway …


That looks like a fill pipe for an underground oil tank, was there another long skinny tube that appeared out of the ground near this one?

I tend to agree but with no visible vent pipe, who knows.

Was an attempt made to open it?