What are some good cl field trips?

My cl is taking an end of the year field trip and the eighth graders get to choose it. I live in Sum Prairie/Columbus Wisconsin (near Madison) we can go anywhere, but our budget is $80 per person. We may also do a fund raiser, but we probably won't get much from that. We want to refrain from the Dells this year as we always go there. There would be a total of 14 students and 3-5 chaperones plus a teacher. Any suggestions as to where we can go?