It's not possible to protect against destruction by human beings over these timescales, irrespective of whether people remember what the artefact means.
Any such project can only use engineering to provide assurance that the result should last that long _if_ no-one destroys it.
It's not possible to protect against destruction by human beings over these timescales, irrespective of whether people remember what the artefact means.
I think once something is more than a few hundred years old then humans will automatically try to preserve it unless there's a good reason not to (reuse of scarce resources, ideological issues, etc). The challenge is getting something to last long enough for our innate desire to preserve history to kick in.
Any such project can only use engineering to provide assurance that the result should last that long _if_ no-one destroys it.