In Denmark, our Gymnasium / HF is sort of like a mix of American high school and college. We have up to 9 or 10th in basic school, and then you do 3-2 years in Gymnasium before University.
I went to several high schools, but I enjoyed my time at Det Fri (The free gymnasium). It was a sort of anarchist far-leftist institution, completely covered in grafitti art everywhere. And I do mean everywhere.
The school was structured as "alternative education". The school board consists of students, and basically everything is decided by the students. There is a head principle and a teacher staff, but they don't decide how the school is structured. The curriculum is set by the state, but the students vote and decide how they want to study and have classes structured.
The school had some of the highest grades on average in all of Denmark despite being seen as "radical".
What impressed me the most about it, it that there was a lot of people there who really was unable to function in the normal school system. People who had all sorts of problems, socially, mentally, physically. But this place gave a lot of room to people, and as a result, nobody really bullied you for being a freak or different. That was really nice about it.
It didn't have a lot of tolerance for anybody who wasn't extremely far-left thou. It was quite a echo chamber, but that was by choice. It's sort of a stronghold in Copenhagen for those who are political and very far left.