10,000 Year Danger Marker?
Here's a real-world puzzle for students of precautionary cognition.
The US Department of Energy's "Waste Isolation Pilot Plan" is a program to store nuclear waste in an area that will remain toxic to humans for at least 10,000 years. The planners need to place markers that will discourage vandalism and reliably convey danger for 400 generations.
The Edvard Munch aspect of the image above seems promising, but English text?
They also considered planting immense spikes to inspire awe as well as aversion:
To explore some of the options the planners have considered, see here.
What would you propose?