I've been there for consults during residency. They're depressing places. Most people there are harmless, but some are so medicated that they look like they're sleepwalking. I always kept my guard up, though. Little things like not letting a potential crazy get between me and the door. They usually do a good job of separating out the violent ones, who are sent to places that I assume are a combination of jail and a psych ward.
I also interned at a halfway house for people who were transitioning out of psych hospitals but weren't able to live on their own yet. That was a lot more chill.
A friend of mine had pretty bad depression and was receiving in-patient electroshock therapy at a place that was nicer than where I trained, but you still had the feeling of being around some over-medicated people.