Concrete disturbed, decorated, danced on.

On Valencia, between 17th and 18th, laid out so that people could read cryptic messages whether they were heading north or south. Photo by Heather Smith

In Dolores Park, the just-torn-up rubble from the playground was amazing. As I walked along it, I could hear parents all around me trying to justify the playtime destruction to distressed children. Photo by Heather Smith

The Reasons You Gave Me, says the sidewalk running along the western side of Dolores Park, Is this meant to be participatory? I could come up with a few. Photo by Heather Smith

Discarded shoes, on the steps leading up to Dolores Park. Perhaps more clothing will follow. Photo by Heather Smith

I looked up from the pavement, and there found a group of people learning basic tango. “Once you learn this” said the instructor, Donilo, who teaches the class every Sunday at 2 p.m., “You can dance with almost any drunk person. And that’s a useful skill.” Photo by Heather Smith

On Dolores, between 18th and 19th. It’s a different font, but the numbering suggests possible correlation between in and “The Reasons You Gave Me.” Photo by Heather Smith

On Shotwell, between 19th and 20th, an amorous piece of sidewalk is fading into illegibility. “Feel me up and Down” it implores. Photo by Heather Smith