What are some "must see's" in Gatlinburg/Pigeon Forge TN area?

My Fiance and I got a cabin for the weekend of July 4th. We haven't seen eachother in 3 months (both Navy) and i deploy to Bahrain in a few weeks. He took leave to see me, and it happens to be our one year anniversary of dating one another! What are some fun things we can see/do? I've been to Gatlinburg twice, but I was younger and it was winter. Thanks!!