Best Preserved Areas Of Normandy Bocage

I'm currently staying in Suisse-Normand near Falaise. It is beautiful countryside, and just at the lower end of the Normandy bocage.

I recently read a book on the Battle for Normandy which talks a lot about the sunken lanes and huge hedges of the bocage which really piqued my interest. There are sunken lanes and hedges here, but not on the frequency or scale mentioned in the book.

I'm assuming (as in the South of England) that most of the sunken lanes have been tarmaced and widened out of existence, I've driven through the area West of Caen without finding much more than the occasional track, so I'm wondering if there are any particular areas where a good concentration of these lanes are still in existence and accessible? Or is it just a scattering of a few isolated lanes and tracks left?

Notes

• there is a heat map here that is interesting but nowhere near detailed enough to answer my question.
• IGN publish paper and digital maps, but they are pretty weak when it comes to footpaths (except long distance paths). They seem to ignore a lot of the local paths and tracks.