My husband and I are looking for a fun family vacation destination within a reasonable driving distance from Dayton Ohio. We will be taking three children from home (ages 17, 13 & 10) and hopefully our 20-year-old college student daughter and married-with-husband-and-toddler daughter will join us. We have been looking at Gatlinburg, and the choices seem overwhelming. We are looking for a casual, laid-back area with lots to do. Any suggestions?