The Mont des Arts fills social media and tourism search engines and has almost become an icon of Brussels in the international imagination. Yet its current form is quite far removed from the original 1957 project. In the 1980s, a third of its surface was cut away to make room for SQUARE. In the remaining part, planting and furniture were significantly altered. An essential part of the project, which offered spaces for relaxation within informal vegetation — birch groves and lush perennial plantings with colourful blooms — was removed in favour of the formal section. The composition lost its overall balance, originally based on the tension between formal and informal. The visit addresses the notion of landscape heritage, highlighting both its fragility and the relative ease with which it can be transformed, making it even more vulnerable than architectural heritage.