13. Neza-Chalco-Itza (Mexico City, Mexico)
Neza-Chalco-Itza, located on the outskirts of Mexico City, evolved from informal settlements into one of the world’s largest urban agglomerations, with an estimated population of approximately four million. Despite improvements over the years, the area continues to grapple with challenges such as crime, flooding, and limited access to clean water. Efforts to address these issues have been ongoing, but residents still face significant hardships (finance-commerce.com).
