The Post-Human World

Alan Weisman becomes the latest (see Mike Davis in Dead Cities) to imagine the world after humans:

A million years from now, a collection of mysterious artifacts would remain to puzzle whatever alien beings might stumble upon them: the flooded tunnel under the English Channel; bank vaults full of mildewed money; obelisks warning of buried atomic waste (as current law requires) in seven long-obsolete human languages, with pictures. The faces on Mount Rushmore might provoke Ozymandian wonder for about 7.2 million more years. (Lincoln would probably fare better on the pre-1982 penny, cast in durable bronze.)

Interestingly, in Savage Dreams Rebecca Solnit recounts attempts to figure out how to write "This is nuclear waste! Stay the hell away!" in a way that any conceivable intelligent visitor at any point in the future could understand. As I remember, there was a contest for anyone interested to try that didn't turn out too well.