The Boulder Creek Festival
It was pretty crowded. Be prepared to be run over by multiple strollers and dancing hippies.
But fun! The Boulder Creek Festival has several performance tents, a farmers market, rides, a rock wall, craft and clothing booths, and at least three gyro stands. After buying your fill of jeweled earrings, tie-died onesies, and cloth purses, grab lunch and people watch down by the creek.
The best part was a guy in the creek making seemingly impossible rock formations.
The Boulder Creek Festival is held annually over Memorial Day weekend on Canyon between 15th and 9th. There is free (!) parking off Canyon Street, although you may have a bit of a trek from your car to the event. If you are reading this on the day I posted it and are going tomorrow, get there early to cheer on the Boulder Boulder 10 K runners, or at 4 to participate in the Rubber Ducky race down the creek.