Mexico City is encompassed by land and air, by mountains, hills, volcanoes, and haze. But it cannot be encompassed by words. Or not by mine. I saw a fraction of this enormous city. But I do have impressions, and those I will share. Dogs I had no idea, but there seemed to be almost as many dogs as people on the sidewalks of the La Condesa neighborhood and nearby. It seems half of the people must have dogs. Dog walkers strolled with packs of ten, or let them lounge together in one of the many parks. People briskly took their dogs on laps around the block. We sat in a park and watched a woman play fetch with her two Belgian Malinois until a…