We did our first Tauck Bridges trip when my youngest was 4, and he was the youngest in the group, but he had traveled internationally before. We did the Costa Rica itinerary (lots of activities, no museums, not a long flight from Texas and the same time zone for us) which was similar to the ABD at the time, and he was the kind of kid who was willing to zipline by himself at that age (the next youngest was 6 and declined). We pretty much spent all of the on your own time in the hotel pools, but it was an incredible trip. We are doing Tauck Ireland in June and he is now 6 (but we have since done the Baltic on
Disney Cruise Line) and are doing our first ABD, the Danube River cruise next summer when he is 7.