>>2699455France, not far from Switzerland, relatively flatter. I've had very nice trips in my highschool years, parents would cut us a lot of slack if we had a cell phone, told them where we went and were back on time. We (almost) always stayed on paths, sometimes got confused going through fenced properties (but when there is a right of passage you have, well, the right to go through) but never got lost.
There were a lot of hills, small mountains, rivers, lakes and abbeys and castles, sometimes ruined but not always. We sometimes knew the owners or keepers. There were also some villages that had economically collapsed in the last centuries and still had a lot of 16th/17th century buildings. I've been a boyscout there also, we had a lot of fun, though the weather was often rainy.
I've also been on the Swiss-German-Austrian border in Bavaria in those years, on the Constance lake, magnificent region. I was younger and we were usually with adults, but still managed to get chased by young bullocks, got into trouble in swamps and had the greatest difficulty understanding the local dialects. Bavarian law is very relaxed regarding camping, especially compared to the rest.