One of the few places to find actual underground murals in the Mission these days — in other words the kind explicitly not approved by some shady collective — is Osage Alley. Instead of stale and increasingly contrived attempts at political statements, at Osage Alley you’ll mostly find the funky old school and copyright-agnostic murals that the Mission was once known for.
The murals on this two and a half block long alley change frequently. For some of the previous art, check out the images on Google Street View.