SAN FRANCISCO - For more than 40 years, Twin Peaks Tavern has been known as the "Gateway to the Castro," but when the business was bought by a lesbian couple back in 1971 and transformed into a gay bar, it was revolutionary.
RELATED: San Francisco doctors reflect on evolution of AIDS treatment
The tavern, facing San Francisco's Market Street, was installed with huge plate-glass windows, the first bar in the country to let the outside world see in.
"And at that point gay bars were in a dark place. There were still police raids," said President of the San Francisco Historic Preservation commission. "Relationships between men and women of the same sex were criminalized. You didn't want to be in a public place."
Wolfram explains how Twin Peaks was more than just a bar. It was a meeting place for gay rights groups and activists.
The San Francisco Board of Supervisors honored Twin Peaks as an official historic landmark in 2013.
"It's just a core part of the LGBTQ identity in the Castro," said State Senator Scott Wiener.
Wiener, who was a supervisor at the time, sponsored the legislation. "It had these beautiful, huge windows and so it was a symbol in a way of an awakening of our community and coming out and being more open to the rest of the world and not being afraid," he said.
Wiener told ABC7 News the plaza in front of the tavern is still a popular spot for rallies and protests.
Sam Ensley has been coming to Twin Peaks since it opened. He moved to San Francisco with his partner to live somewhere they could be themselves. "To take all this and actually see out, and see people embracing, see women embracing and men embracing. I mean, oh my goodness," Ensley told ABC7 News.
He credits Twin Peaks with paving the way in the gay rights movement and with what he sees today -- bars up and down the Castro with open windows, patios -- filled with gay and straight friends where nobody has to hide.
Click here for more stories, photos and video on the ABC mini-series "When We Rise" and the stories that inspired it.