Lets see, you've got the rock hall of fame and... uh... that's all I did when I was there. Granted, I was only there for 5 days and I was working every day, so I didn't get much time to explore, but the rock hall is the only place I went. It closes kind of early (I want to say 6PM), but is open later one day of the work week, I think.

No offense to the people of Cleveland, but I didn't see much to do when I was there.