In early 1967, upwards of 20,000 hippies, artists and Hell's Angels gathered in San Francisco's Golden Gate Park for a "Human Be-In" to protest the bourgeois mentality of the older generations and, specifically, a California law passed the previous year making LSD illegal.

The Grateful Dead, at that point the Haight-Ashbury's official house band, performed, Allen Ginsberg led the crowd in chanting mantras and Owsley Stanley distributed acid out to the crowd. It was one of the first forceful, large-scale expressions of San Francisco's growing hippie movement and presaged the Summer of Love that unfolded in the following months.

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This coming weekend, another group is picking up the Human Be-In banner and affixing it to a free, unauthorized concert in Golden Gate Park. Calling themselves Space TranSFormers, these demonstrators will protest what they see as the growing commercialization of the city's public spaces.

"This is a big tradition in San Francisco--people gathering freely to share music and discussions...We feel like it's kind of fading away," organizer Ryan Rising told the San Francisco Examiner. "We will be thinking about how to grow our own food, heal each other with herbal medicines, build natural structures...this is about reaching a permanent relationship of balance with the earth."

The event features a live music and DJ performances, DIY art projects and workshops on subjects like rainwater harvesting, bread making, Reiki, ballroom dancing and "living without conventional currency."

"Organizers call it a protest against private concerts on public land, which is why everything is free," reads a post on the event's website. "It is a gathering to transform space, cultivate community, and to simply 'be.'"

Space TranSFormers are, among other things, against the closure of the Haight-Ashbury Recycling Center, opposed to the installation of artificial turf on the soccer fields near Ocean Beach and angry at the Parks Department's increasing fees and imposed attendance caps that resulted in the cancellation the annual Power to the Peaceful Festival for the second consecutive year.

The event begins on Friday, September 14 at 3pm at Kezar Gardens in Golden Gate Park. It's scheduled to last throughout the weekend.

Check out these pictures from San Francisco's hippie heyday:

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  • Haight-Ashbury

    Carrying a loaf of bread, a guitar and a knapsack, a hippie walks down the street away from the Haight-Ashbury district of San Francisco, Oct. 16, 1967. As the last of the summer weather moves out, so does the influx of young people that came in with it.

  • Haight-Ashbury

    An unidentified demonstrator, in the Haight-Ashbury, is helped to his feet by police after being clubbed down on to sidewalk, July 18, 1968, San Francisco, Calif. Rock throwing looters clashed with police in second night of violence in famed citys section.

  • Haight-Ashbury

    Young hippies straddle the sidewalk as an elderly woman, a long-time resident of the Haight-Ashbury district, walks by in San Francisco, Calif., on April 25, 1967.

  • Haight-Ashbury

    George Harrison, a member of the British pop group, the Beatles, pays a surprise visit to San Francisco's famed Haight-Ashbury hippy district, on Aug. 8, 1967.

  • Haight-Ashbury

    Tourists test the hippies philosophy of love for everybody, April 13, 1967, Haight-Ashbury district, San Francisco, Calif. A bus company recently started tours through Hippie Town. In protest the hippies have staged two demonstrations and sit-ins at intersections, tying up traffic for hours.

  • Haight-Ashbury

    Hippies in the Haight-Ashbury district created a quite a traffic jam with their Easter parades, March 26, 1967, San Francisco, Calif. A few wounded up in jail. Here officer drags a would be traffic blocker away by the scuff of his neck. Thousand of sight seers crowded the district just to that is going on. The people in this photo are unidentified.