I can't see getting so snotty about the tourists.   I admire anybody who gets off their butts and takes their kids to see some new stuff, particularly historic. They are becoming a vanishing breed. The real morons are down at the nascar races or staying home playing electronic games.   

Perhaps the nieces could look beyond their own boredom and enlighten the poor dears instead of being exasperated by them. And yes, I've spent summers answering tourist questions, loved it.