Behold: a whimsical portrait of 1970's San Francisco, when you could jiggle and flap your hang glider right off a cliff near Fort Baker, naked as a jaybird. We highly doubt anyone told this guy to put a towel down before he stuck his landing. [Note: possibly NSFW, if your work is against naked thigh muscles.]

The photo comes to us by way of Self Contortion on Tumblr (via SF Neighborhoodr). If you happen to have a source for it, do let us know.