The modern traveler, when visiting great cities, is often struck by how "familiar" a place can seem on a first visit. With exposure to television and movies, we can be walking or driving down streets whose names we've heard hundreds of times, see landmarks that seem slightly unreal because, now, they exist in the third dimension. We can feel at home in places our ancestors would have thought of as being as strange as Mars simply because we already know what the streets look like, the people sound like, the food smells like. Our exposure to images can even distort perceptions of our own city when we come across something that seems a bit too much like a film set. Is it real? Where are the cameras? How did this happen to be here? This can happen surprisingly often in San Francisco, a place that can be a bit too "cute" for its own sake. From sidewalk cafes to flower stands and cable cars, we're always in danger of becoming a larger version of Carmel-by-the-Sea. Thank God for some of the "edgier" parts of town. All of this was brought to mind by a couple of places on a recent stroll. The first is the old Mission Police Station on 17th Street. It looks like it could be in Havana. The funny thing is, the place gets more authentic the closer you get. It has an incredible amount of character. No film set, this. The second "scene" is an alleyway called Harlow Street off of 16th Street near Church. From the gray shingles on the building, to the shop with its seven digit phone number and the ancient Chrysler products parked on the street, this place really makes you look around for the cameras. Someone in this alley likes to collect cars and has worked out some method of keeping them parked in the same place all the time. Both places are like doorways into another place and time and for that I'm very grateful.