@infobeautiful Some Roman roads were laid straight on top of existing "Celtic" log roads in Britain, France and lots of Europe.
There was a Pan-European Celtic Culture reaching to northern Turkey. Romans hated it, lied about it and tried to "genocide" the Helvitians as they migrated to "Switzerland" to avoid Slavs.
Romans get credit for lots of Greek, Celtic, Egyptian etc stuff, because victors & Colonial powers write most of the history.