Giant, jagged earthwork berms should surround the area. Dozens of granite message walls or kiosks, each 25 feet high, might present graphic images of human faces contorted with horror, terror, or pain (the inspiration here is Edvard Munch’s Scream) as well as text in English, Spanish, Russian, French, Chinese, Arabic, and Navajo explaining what’s buried. This variety of languages, as Charles Piller remarked in a 2006 Los Angeles Times story, turns the monoliths into quasi-Rosetta stones. Three rooms—one off-site but nearby, one centrally located, and one underground—would serve as information centers with more detailed explanations of nuclear waste and its hazards, maps showing the location of similar sites around the world, and star charts to help intruders calculate the year the site was sealed.

It’s impossible to say what apocalyptic event might separate 21st-century Americans from our 210th-century successors. Successors, mind you, who could live in a vastly more sophisticated society than we do or a vastly more primitive one.