El DF... what comes to mind when you hear its name? Smog? Over population? Quesadillas that don't necessarily have queso? Protests? Rubbish? Congestion? All of those answers would be valid. Mexico City is one of the largest and most populous cities in the world, but unlike Tokyo or New York (I imagine, never having been to either), the capital lacks a sleek, streamlined feel. Like in most large cities, people always seem to be in a rush, often not even looking when they cross the road in the city centre, just wandering across.