The heavy metals in the muddy river bottom may poison the fish for a century. Every century or two a tidal wave will wash away houses that stand on the hillside below the marker stones placed there by forgotten ancestors who learned the hard way where those stones should be placed. Inside these deep caves are the barrels from the nuclear plant. It's too simple to say that the web is only for thinking and talking now, but I don't know how well we've done so far in linking the live action here to the old knowledge and the knowledge that needs to be remembered that resides in the old media. It's something to keep thinking about.