I wonder if it wouldn't be more helpful to try and design a Geiger counter that could last 10,000 years. I'm picturing a ring of large obelisks made out of some

I wonder if it wouldn't be more helpful to try and design a Geiger counter that could last 10,000 years. I'm picturing a ring of large obelisks made out of some radio luminescent material. Actually it would probably be better if it changed between ugly colors rather than glowed. If it's pretty people would demolish it before the ribbon is cut. Have all your pictograms try and communicate that some color = you're going to die, as well as "If you move much beyond this point, you're going to die _fast_." Here's the important, albeit macabre part: After about 100 meters towards the center of the exclusion zone, you need to store enough radioactive material, preferably near Geiger obelisks, that going there will kill you _very_ quickly, for 1000's of years. Quicker the better. People need to associate the deaths with the area! I assert that when 50% of people get cancer a month after entering a dump zone, it's hard to associate those illnesses with the cursed area until a lot of people are doomed. If 3 people go somewhere and none return, it becomes part of local lore.