Cultural Diversity

I live in a very rural area with ZERO diversity. We can't move because our children have other parents here and we share custody. Unfortunately those other parents are racist & homophobic influences. And even though we talk to the kids about these subjects, it seems that it's not enough. There was an incident at a waterpark that made us realize how small and closed off our kids world is.

Any suggestions on how to introduce our kids to other cultures?