Hi Roy, It is what I would call a 'personal reflection' book, judging from the first two readings, here is a taste of The Guardian review....

"And then there is On Silbury Hill's earnest hippy sensibility. "I have always been susceptible to the tofu-knitting, yoghurt-weaving world," writes Thorpe, and so it proves. It's impossible to take seriously a narrative that includes both a teenage fantasy in which he imagined he was a Neolithic man returning from a hunting trip in the forest ("my woman running out to greet me with her lovely ripe smell of unwashed flesh") and an irony-free description of his adventures in hypnosis"

The reviewer is slightly damning in her summing up, if you have ever read Macfarlane, then this new 'landscape' book follows in the same drift..
I like them as a matter of fact, and "landscapism" is just a new genre..

http://www.theguardian.com/books/2014/jul/20/on-silbury-hill-adam-thorpe-review