New to RV,when traveling how do you know what areas to avoid

Someone once asked for campground recommendations for Memphis, TN. A visitor to our fair city stated that he recommended the campground at Graceland. Since I live in Memphis, I know that area. I strongly advised against that area. The visitor actually came back and said the campground was perfectly safe, get this, because they had armed guards at the gate! My response was that I didn't want to camp where they HAD to have armed guards at the gate.