The cities you mentioned were mostly developed recently with a solid plan. The primary purpose of those European cities weren't being a tourist destination. Whe

The cities you mentioned were mostly developed recently with a solid plan. The primary purpose of those European cities weren't being a tourist destination. When the Notre Dame was built 800 years ago, they weren't thinking about 21st century tourists. A lot of tourist attractions in European cities were built before the airplane/car era so preparing for a massive influx of tourists probably didn't cross their minds.