I’ve always dug that old Airstream on the roof of a building in the Tenderloin and I just assumed everyone in SF knew about it and lately I keep asking people if they know about it. Anyhow, it’s on the roof of 130-132 Turk and you can see if from the street. Legend has it that it was an old gay bath house in the day, but another story (a la REO Speedwagon’s Take it on the Run style of knowledge dissipation) is that there are four Irish brothers that own the building and they got it up on to the roof to be their new clubhouse. Related: http://sf.curbed.com/archives/2009/08/14/wtf_moment_of_the_day.php
Or donate to David and Lawrence’s wedding registry and ask them about living in the rooftop Airstream: https://secure3.convio.net/hrc/site/Donation2?df_id=9784&9784.donation=form1&JServSessionIdr004=byy4401t52.app304a
