What is this...drain?

[Peterk]

Does anyone know what this is? We found it under the subfloor when ripping out our basement. I don't know if this is something I need to deal with.

This is in the ground 6 inches from an outside wall. The hole itself is 4 inches in diameter.
Home was built in 1974.

It's on the opposite side of the house from the HVAC, furnace, gas line, and water heater, and all water pipes/drains.
There is already a floor drain in the house besides whatever this is.

 

[Diehard]

Well it appears to be a Plumbers test plug in a clay drainage pipe. Where the pipe goes, who knows, but it was sealed off with the plug.

 

[Geofd]

that would be my guess its probably drain related

 

[frodo]

turn the wing nut, open it and looky look

 

[Diehard]

Don't do it!

 

[FishScreener]

Ok, thought about it a bit more, and looked again at the pictures. Now think it is a test plug installed in a clean out, with dirt and debris on it.