Mexico City contains multitudes that single visits cannot absorb. Altitude affects first days — hydrate constantly and pace expectations. The metro moves millions daily at almost-free prices; rush hour should be avoided. Street food ranges from sublime to risky — follow crowds and cleanliness signs. Taco prices indicate authenticity: under 20 pesos suggests locals, above suggests tourism. Uber dominates transport; pink taxis have safety concerns. UNAM campus deserves architectural pilgrimage regardless of academic interest. Anthropology Museum requires multiple visits for proper absorption. Neighborhoods define experiences: Roma for hipsters, Coyoacán for bohemian, Polanco for luxury. Archaeological sites within the city (Templo Mayor, Teotihuacán nearby) justify serious time. Pulque and mezcal culture provides authentic drinking experiences beyond tourist margaritas. Traffic makes scheduling unreliable — build buffer time everywhere. Sunday markets in Coyoacán and San Ángel deliver crafts and food in beautiful settings. Air quality varies dramatically by season and day — check forecasts.