Just got thinking the other day about dystopian future fiction, and wondered if any writer had ever considered using modern landfill sites as 'mines' for their future civilisations. These civilisation will live in primitive circumstances by today's standards, and will want raw materials for tools, etc. It seems to me that these sites (especially if you dig down deep enough to bypass most things thrown away during our the recyling era) must contain a lot of very valuable stuff. Mostly metal, of course—especially the kind that doesn't rust. But plastics as well. The kind that doesn't degrade. And even glass? Or baby diapers. Okay, that sounds pretty awful, but many years will have degraded the organic components and just left the fibres, which might be very usable. Of course methane gas and possible collapse of the sites would make them dangerous, but modern mines contain dangerous gases and collapse as well, and it doesn't keep mining from happening. It occurred to me that these sites might become valuable and perhaps a fountain of 'wealth' for whoever controls them. I have no intention of ever writing a dystopian novel, but I just wondered if this idea had legs, or if somebody else has already written this kind of setting.