This is interesting: https://community.ricksteves.com/travel-forum/general-europe/back-doors-and-overcrowding-a-world-view
From the Man himself
A fundamental part of enjoying travel in Europe is finding places that I call "back doors." When I first started traveling, back doors
to me were Europe's undiscovered corners and untrampled towns that
had, for various reasons, missed the modern parade (like Dingle, on
Ireland's western edge, or Portugal's Salema, tucked away on the
southern coast). But now, with more sophisticated travelers — and more
travelers overall, now that so many more people around the world can
afford to travel — worthwhile places rarely go undiscovered. And
certain destinations that I've long raved about now suffer from
This is a pretty Western Europe centered attitude. Or maybe better put "traditional country destinations" centered attitude.
Yes, as more travelers come worthwhile places in the traditional country destinations rarely go undiscovered and what were once Back Doors do now suffer from congestion. But to assume that is the case in ALL of Europe promotes a sort of narrow view of Europe.
So how, in today's Europe, do I still find back doors? These days, my approach is less about discovering the undiscovered and more about
using thoughtful travel to get beyond tourist traps, sidestep crowds,
broaden perspectives, and experience a part of Europe that most
travelers miss. Here are some ways you can still do that.
In other words, since the traditional country destinations have become so overly touristed (is that a word?), rather than expand your horizon beyond the common countries, we should redefine Back Door to help keep the traditional country destinations more attractive.
Remember when the Cinque Terre was Ricks great Back Door discovery for tourism? I haven't been there myself but the area was the source of a lot of press years back on how tourism negatively impacted the area. But rather than searching out new places of similar character RS redefined the definition to continue the theme with his tours. A lot of what made Cinque Terre so fascinating still exists along the Eastern Adriatic coastline. Then, what Cinque Terre was to Italy, Bulgaria is to Western Europe.
For those that got a lot out of small out of the way places where life still continued as it had for generations, and where tourists were few, where every street corner didn't have a Star Bucks or a McDonalds; the options still exist. But it takes a little wider world view to find them. BUT, nothing wrong with Italy or France. I love them too. This is an option not a criticism.