The former homes of the guys from the Grateful Dead and Jefferson Airplane, or Janis Joplin and the Mamas and the Papas, have become destinations of a modern-day pilgrimage. The kids at Haight-Ashbury aren’t flower children anymore — some are just tourists, others just drug addicts

In the nearby Castro — one of the birthplaces of the modern gay rights movement — people still grieve the death toll AIDS took throughout the ’80s and ’90s. They still decorate the walls of cafés and nightclubs, giving a bitter edge to the long-gone days of free love and careless orgies.

We meet one of rock’s greatest voices in the Joshua Tree National Park: Eric Burdon, who gave the world “The House of the Rising Sun,” “Spill the Wine” and “Warm San Franciscan Night,” he recalls the LSD trips of his youth, how times were gentler back then, but how the possibilities of modern, state-of-the-art sound technology aren’t too bad either. In the old university and protest town of Berkeley, we meet Country Joe McDonald, the man who famously chanted “Gimme an F…” on stage at Woodstock in 1969. He still performs that chant today, alongside his early environmentalist anthem “Save the Whales” — only for slightly smaller audiences now

In Haight-Ashbury we talk to John Perry Barlow, the man behind the lyrics of most Grateful Dead songs, who lived there at the peak of the hippie haze and later became an internet guru. No more flowers in his hair, but now plenty of new pie-in-the-sky ideas.