SVN West, San Francisco, CA https://svnwest.com/
I never made it to San Francisco’s Fillmore West (although I did see the Grateful Dead at the Fillmore East in 1972. It was epic). Anyway, formerly home of the Fillmore West and the Carousel Ballroom, SVN West is located at South Van Ness and Market Streets and offers over 100k of event space on three levels and an outdoor rooftop. If I wanted to have a party with 4000 guests… that is where I would start.