|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
Belgium, officially the Kingdom of Belgium, is a country in Western Europe. Its capital is Brussels. Many Belgian witches and wizards attend Beauxbatons Academy of Magic in France, presumably due to a lack of a wizarding school in their own country.