Let me let Wikipedia explain:
Sebald's works are largely concerned with the theme of memory, both personal and collective. They were in particular attempts to reconcile himself with, and deal in literary terms with, the trauma of the Second World War and its effect on the German people. In On the Natural History of Destruction he wrote a major essay on the wartime bombing of German cities, and the absence in German writing of any real response. His concern with the Holocaust is expressed in several books delicately tracing his own biographical connections with Jews.
His distinctive and innovative novels were written in German, but are well-known in excellent English translations which he supervised closely. They include Austerlitz, The Rings of Saturn, The Emigrants, and Vertigo. They are notable for their curious and wide-ranging mixture of fact (or apparent fact), recollection and fiction, often punctuated by indistinct black-and-white photographs, which are set in evocative counterpoint to the narrative rather than illustrating it directly. All of his novels are presented as observations and recollections made by Sebald while travelling around parts of Europe. Two literary projects, imagined though never written, by the Argentinian author Jorge Luis Borges, are keys to the work. The first (described in the short story "The Garden of the Forking Paths") is a maze-like anti-plot embedded back and forth within a conventional novel, or series of novels. The second (from the preamble to the tale "Tlon, Uqbar, and Orbis Tertius") is a "novel in the first person, whose narrator would omit or disfigure the facts and indulge in various contradictions which would permit a few readers - very few readers - to perceive an atrocious or banal reality ". The fact that Sebald, a professional literary academic, managed to construct all this in minute detail and with Bach-like grandeur, then foist it on his unsuspecting fellow de-constructionists, illustrates another key to understanding the oeuvre.... an inscrutably dry, mischievous sense of humour!
The book, as with much of Sebald's work, regards the memory, and though this book is melancholic, and the theme regards the destruction of nature by man; and if not nature, then the destruction of man, and serves to raise the question of where does the fact lie.
On the rear of the 2002 copy are the three words that designate what this "book" is all about: Fiction/Memoir/Travel.
There's 296 pages of a several day stroll through the Suffolk landscape, relating personal moments of Sebald's own life that emerge in his psyche (allegedly) as he wanders, and historical dioramas that relate to the melancholia and downward spiral of man, but draw us constantly back to some undefinable thing: why is he trudging, why is he spewing these memories, why am I still reading? More importantly, some of the facts of history aren't true, but how are we to discover that?
That final question is ever more intriguing in this digital age, where places such as Wikipedia and Media are busy presenting you with the "truth", and doing it often enough to make sure you agree with them. Wikipedia in itself is at the mercy of the public writing what ever it will - we've all heard the scandal of Capitol Hill Government workers altering Government based pages on Wikipedia, to subvert meaning, or cover up some issue, or description.
So, what is the truth, and what is it's purpose? Is it, like with Sebald, something to be played with for the sake of matching up the main theme and tying off a chapter's topic?
If one was to write one's own psycho geographical work, would one look for synchronicty in topics to discuss:
It was Wednesday night and I'd been on the road for a good hour, listening to the randomised playlist of my MP3 player and watching, somewhat passively, the flash of white light streaming towards me from the other carriageway and the burst of reds pulling around me. I dipped into the outside lane, floored the pedal and fell into procession behind the car in front. Another sped up behind so that all I could see were the bright double halos bearing down upon me , angels in the dark, come to bring their retribution for some crime I was- 87-88-89mph. I signalled to swing left, we were going too fast, and I having got caught up in following the car ahead, and forced ever onward by the lunatic behind had long ago crossed over my own threshold. I had to get out quickly, and so pulled over.The alternative to finding a synchronicity is to take a topic and change it... just tweak one element to make it fit. Say, for example, as I've done above - for it was really Cain who killed Abel, not the other way around. That's actually a really loose example, but it gives you an idea of what I mean, and how psycho geography works. It's oft a little crazy, but there's something about it, in the history it unearths and the questions it raises on purpose.
Except that a lorry on the inside lane was signalling and pulling out into the middle lane, where the two of us were bound to collide. As I swung in, flashed hard on the break to avoid the impact and the angels that had hounded me for at least a mile flew past, I was reminded of the heartache of Abel. After all, I was only keeping up with the guy in front, and trying to appease the one behind. I wasn't really speeding, my driving not forced to dangerous measures, since it was all out of my control. And yet I was endangering lives; perhaps my own, perhaps not. I was certainly thinking of only myself and how to keep up with the Jones's.
Abel had been of a similar mind, in that backward time long before machinery and death by metal. He may not have been driving so very fast, but he was yet in a race to provide his offerings to God. Was it not that need to be somewhere - mine to be home, his to be in the good graces of God - that spurred him to kill his brother, to take a life so that he might be that little bit closer to his goal?..