Which is the No 1 cleanest city in the entire world

If you want a city that has no litter, look no further than the Nordic capital of Helsinki. The city has a relatively mild continental climate located more than 1000 meters above sea level, and the proximity of nature helps keep the air clean in this beautiful city. The residents are also very committed to protecting the environment, with many people avoiding littering and recycling. With over two million square feet of rooftop gardens, Calgary has some of the cleanest cities in the world.