I'd heard stories of "The Vats" in San Francisco for decades.
It was an abandoned Falstaff Brewery that had become a show space and scum condo in the early '80s, with a dozen punks living on top of each other, some of them even paying rent.
There were four floors full of these vats, with about 12 kids living in each one. The entrance to each unit was the small hole that had been used to clean the tanks back when it was a functioning brewery, although a few had bigger holes smashed in them in order to fit band equipment inside.
I was young enough to have missed this punk landmark and it was torn down in 1983. I thought I would never see them at all until I stumbled across this old Pop-o-Pies video on YouTube that provides an incredible tour of some of the different rooms, copious amounts of shitty graffiti, punks popping out of holes, and even a bonus shot of the old Hunt's Donuts "Open 25 Hours" neon sign. It is truly glorious.