It may come as no surprise that the crowded streets of Mumbai are considered some of the dirtiest in the world, but the Indian city is not the only tourist hotspot to receive such negative comments.
TripAdvisor conducted a recent survey to rank the cleanest cities in the world based on the cleanliness of each locale's streets. The results, compiled out of more than 75,000 responses by recent TripAdvisor reviewers, paint a dirty picture of tourism around the world.
While the U.S. is home to some of the least polluted cities, only one urban center in the U.S. made the list of cleanest cities in the world. Can you guess which one it is?
Check out TripAdvisor's full list -- from dirtiest to cleanest -- in the gallery below, and also see which cities the website rated the friendliest in the world.