Comment by dbspin

Finally a solution to long term nuclear warning messages! [1] All we have to do is merely create an ultrasound emitter that works over a distance of meters and lasts several thousand years. Then assail our post apocalyptic adventurers with a stench so vivid it elicits ancient racial memories of global thermonuclear war.

[1] https://en.wikipedia.org/wiki/Long-term_nuclear_waste_warnin...