Like Ian, I recently acquired this book and have been browsing it in preparation for further excursions; it's long been a fascination of mine. Cope has some thoughts about sacred landscapes and what you can tell about the monuments just by looking at them and feeling what the builders must have intended. There is a nice gazetteer section covering the Belgian and Irish monuments - I really hadn't appreciated that there was so much in the Sligo area! - plus various other parts of Europe, some of which I knew about (Brittany, the Mediterranean, especially the Maltese cart ruts and temples which I saw aged 8) and some of which I didn't (the monuments dotted all over Denmark and southern Sweden). Illustrated with gorgeous pictures as well, some including Cope himself or else his wife Dorian.
The maps are not always terribly clear, and I wonder how much this would actually help me find some of the sites - I shall hope to put it to the test at Wéris some time this year. Also I was puzzled that Cope seems to buy into what has always seemed to me the least convincing bit of megalithic orthodoxy, that dolmens (see userpic) were usually originally covered with earth or stones which has since weathered away; it seems to me vanishingly unlikely that this can be true of more than a handful of them.
Anyway, a lovely book to look at.