I am trying to organize a team building activity for my law firm for our annual retreat. Any ideas?

The law firm I work for takes a firm retreat every July. This year we are going to Branson. We always try to do some sort of team-building activities such as a scavenger hunt, icebreakers, etc. I am looking for some new fresh ideas. We have 8 employees and also take our immediate families so we have a fairly diverse group of people and scattered ages. Any ideas?