On the Magic, there is the Rockin D Bar. Something similar on the Wonder, but can't think of the name off hand. Usually, on weeknights, they are open till midnight, and later (till 1 or 1:30 am) on weekends. At least that is how it was the last couple of times we sailed. They have a 70's night, which usually boasts a big turn out, and is lots of fun. We bring 70's style clothes with us on the cruise, but it isn't necessary to dress that way if you don't want to. We found the clubs to be a lot of fun... but on the 7 day cruise, there were definitely a couple of "slow" nights. Most people seem to leave when the kids clubs close (which I believe is around midnight).