This Place is Not a Place of Honor (2006)
damninteresting.com
damninteresting.com
A plaque with all the UN languages is a rosetta stone, something of obvious intrinsic value. The Periodic table too - to any potential future civilization that hasn't already rediscovered those things, it may be a sought after source of knowledge.
The site is also attractive to those who would wish to use what's there to their advantage - as a weapon against their enemies, likely w/o really understanding the consequences.
Too expensive to launch it into the sun, no other solution (if we're not going to derive the value of reprocessing and actually use it up).
I really couldn't get away from this. I used to do a lot of music. Here's a track I made in '05/'06 off my record: (http://www.hiddenmusic.co.uk/releases/symbolic/, free download);
http://www.last.fm/music/Covert/_/A+Place+of+Honour
Like I said; obsessed...
One of the young people on the team quickly thought out loud, "Sounds like Stone Henge!"
Remember: the earliest known writings are less than 6,000 years old. We're talking about planning for almost twice that. This is an incredibly long period of time, in human terms (though not in geological terms, which is what created the problem in the first place).
Some of the ideas in the original comment thread from 2006 were nice. Make the area inconspicuous, make it extremely expensive to dig up. Why not make it look like a giant concrete dumping ground?
To thwart geological surveys, maybe you could figure out a way to stealth the tunnels or arrange the tunnels in the shape of a warning message.
Perhaps you should make the area extremely inconspicuous and just trecherous to get to for the technologically unenabled (build rivers, hills etc). That way you ensure that mostly only hikers get there and hopefully don't notice the concealed enterance. Of course, that plan could be thwarted if a group of people seek shelter there because of wartime persecution.
I can't see giant monuments doing anything other than enticing people to dig. However, reliefs and images of people dying of radiation poisoning might be less ambiguous.
If future civilizations are technologically advanced, detecting radiation won't be a problem.
If future civilizations have fallen back to the stone age, spatially localized buried nuclear waste is going to be the least of their problems. It would be a rounding error in the annual death rates.