it's such an interesting contrast to most of the west coast where everything is new and modern... even in SF proper most of the city burned in 1906 so there isn't much older than that.
I did the Freedom Trail once and I found it to be very interesting. I remember that during that walk I say a Rolls-Royce drive by and on the ground there was a homeless chap passed out with a cheap bottle of Thunderbird. I wondered at the time, "Is this America?".