Need help organizing a summer family oriented company day! Beer must be allowed, company rules. Any ideas?

We usually have it at a local waterpark but, from what I hear, the employees that don't have kids never really attend. I am in charge of planning this year (and I'm the new girl) and I would like to have almost everyone attend. How can I entice the employees with no kids? I thought about changing locations but Manas, VA is so small and the parks around the area don't allow alcohol.