They have lights so skating at night does happen, but only till 8pm. It's pretty darn fun if you're in the area. San Luis Obispo, California Santa Clara Public Skatepark on E. Santa Clara Street. It's somewhere by 18th street. This park rules and if you haven't seen pictures of it you are avoiding all skate publications.
Snake runs and hips galore.
No grindable lips. It's free and open dusk to dawn. The police have been giving fines if they catch you without your helmet on your head. My advice is to bring your helmet but don't wear it till you see the cops drive into the park. At that time, either put on your helmet or exit the facility.