I didn't mean to put you off going to the rim. My own daughter (9 months at the time) said her very first word there, right at the rim: "Hi!". I'm sure your 4 year old will remember it for a very long time. Cabs take about 30 mins to get from the rim to the airport, hence the hour's wait I mentioned. The quickest round trip, plane - rim - plane, will need 3 hours. I stopped there for lunch in May and that's exactly what it took.