Channel 4 had a gripping programme this evening, Life After People; it featured remarkable scenes of the timeline of the decaying structures of a world after a postulated disappearance of people. In a previous post, Underground London, I mentioned Where London Stood, a site that discusses similar apocalyptic scenarios in literature.
In the same post, I also briefly mentioned Ronald Wright's A Scientific Romance. This literary/SF novel concerns an archaeologist, David Lambert, who finds a document predicting the arrival of the HG Wells Time Machine at a particular time and place. To his surprise, it does. Lambert, with little to lose (he is tormented by memories of a dead lover and the knowledge that he has caught from her the same terminal CJD-type illness from which she died) uses the machine to travel to the year 2500, where he finds himself in the ruins of a stunningly-described overgrown tropical London. Unlike HG Wells' time traveller, Lambert has the equipment and knowledge to gradually uncover the history - a mix of climate change, various plagues, and consequent civil war during the collapse of civilisation - that led to this situation.
If you don't mind spoilers, there's an excellent review by James Schellenberg here in the Canadian SF e-zine Challenging Destiny.