Info from Wikipedia
Golden Gate Park is an urban park between the Richmond and Sunset districts of San Francisco, United States. It is the largest park in the city, containing 1,017 acres (412 ha), and the third-most visited urban park in the United States, with an estimated 24 million visitors annually.
The tradition of large, free public gatherings in the park continues to the present, especially at Hellman Hollow. Since the park's conception, over 5,000 concerts have been held there.
In 2001, Hellman founded the Hardly Strictly Bluegrass Festival (formerly the "Strictly Bluegrass Festival"), a free music festival held in October.