This could all be a complete fallacy and nothing in here be true, but there’s a limit beyond which one stops believing in coincidences and trust that this could have been an actual fact. ‘The Ancient Paths’ and the theories postulated here crosses that limit for me.
The strongest evidence is presented for modern France (Keltika Main, I might call it) but evidence also favours taking these theories of a highly advanced Celtic civilisation into both Britain and Ireland as well. However, it is clear that the Irish section in this book is far more of an afterthought, and I would have wished for a bit more of an expansion on those sections.
The other issue here is that by now this is a relatively old novel, and I do not know what more recent historiography has made of Mr Robb’s novel methodology. Some of the problems the author grapples with also present less of an obstacle for me (Google Maps’ zoom-dependent projections, for example, would be solved by using a specific GIS software), but he still managed to bring across a set of very interesting theories. I am also a fan of the plentiful maps noted here as maps often help the reader understand, and especially in the case of a topic like this one become invaluable.