Last time I was there, someone was openly defecating in front of city hall, next to multiple people shooting heroin. I had to step over someone who had collapsed apparently from drug use, in front of a restaurant entrance, and nobody seemed to care. It's about as close to the third world as exists in the west. I recognize there's extremely nice parts of SF, but most out of state/international guests stay around Tenderloin/SOMA and would never know that.