Winx Club Forever
The school was Avalon's former employer. It can be assumed that the student body mostly consists of paladins, like Avalon himself, based on the name.
Avalon was its leading expert on technical magic with a basis on cognitive analysis and accurate pronunciation.
Then, in "The Mysterious Stone" Professor Avalon is introduced to his new students. Faragonda explains that he is a leading expert from this school and will be joining the Alfea faculty.
However, she and everyone else is unaware that the person she had just introduced was not the real Avalon. It was Darkar's spy who was created by him with the lesson plans of the original Avalon; the spy was tasked with gaining trust and ensuring Darkar's plans would be met. This revelation is not discovered until later when the real Avalon finally escapes Darkar's dungeon after several months of imprisonment (and perhaps, torture). He weakly traveled to Alfea and was able to inform Faragonda of what happened to him.