Ten million visitors can do a lot of good for a city's economy. But if they're all coming at the same time, and visiting the same places, they can also do a lot of damage to places known for their natural beauty. Canada's most picturesque city is dealing with a problem that some of the world's oldest and most iconic cities have faced. It's just too popular. Tourism Vancouver has already shifted its strategies, but do they need to take more drastic action to preserve Vancouver for the people who actually live there? GUEST: Molly McCluskey, CityLab contributor