Iron object at historical society property

[pa-dirt_nc-sand]

Uncovered recently at 1830 historical society property in W PA. Any idea what this is? Could potentially be modern. Just trying to help ID so they can add to inventory or trash.

 

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[noble]

looks like the top off an old stop tap

 

[ticndig]

it's the wrench nut off of a water main valve . you open the lid at ground level , insert key onto square and turn to operate the valve
see part called 2'' wrench nut.