sequestered or the long now

Via the Presurfer, we learn about the resting place outside of the city of Chicago where the first nuclear reactor and associated waste was interred. Researchers at the University of Chicago, working under a top secret commission to bring the powerhouse on-line before the Axis Powers, under the supervision of Enrico Fermi, achieved this first sustainable, controlled reaction at the woodland laboratory in 1942.
The experimental Chicago Piles (CP-1 through CP-3) ran for about a decade until brought off-line and buried in situ—marked with granite blocks and the warning to potential grave-robbers that digging is not advised—though safe for visitors due to the low yield and shielding used for this prototype. Reading this postcard reminded me of the call for submissions several years back on how to handle the nuclear waste of contemporary times, which is much longer-lived and far more deadly and poses a significant problem that the next ten thousand generations of Earthlings will need to contend with. From a vantage point far older than human civilisation itself, how could we ensure that the message of danger and to keep away from today’s nuclear waste disposal sites are imparted to the future? Proposals included a defensive, infernal landscape with sand berms and giant totems of tortured souls, giant steely thorns like the sort that enveloped Sleeping Beauty’s castle, or even a priesthood of sorts to bridge the millennia and warn off the curious and scavengers that indeed you will be struck down by beams of invisible energy if you defile this ancient temple. Can you think of a way to signal danger that won’t be liable to misinterpretation, or is our bequest an unmarked grave?