Key West or Out West

I second the idea that Key West is far more for adults than kids. We've been there twice, love it for a couple of days, but definitely would choose another destination if we had our grandkids with us. The town is all about bar-hopping, food and night-time fun. Yes, there are some things for a family to enjoy, and a trip to the Dry Tortugas would be a definite "must do" for the whole family, but Key West from our experience is a Mecca for party-seekers. The trip to get there is exhausting! Single-lane drive for the length of the keys (which is much longer than it looks on a map!) - both times we went with heavy, heavy traffic! Not enjoyable or relaxing at all! Seeing the ages of your children, I would "go West, young man!" You live on the East Coast, and can always enjoy that, but a trip West with the kids should create some "forever memories"! Just my thoughts.