It was AWESOME travelling with DS the age he was! To watch him take it all in and interact with his relatives, feel the cold of a REAL winter, watching planes on the tarmac, figure out accents, look at odd animals (deer in Dublin's Phoenix Park that he called 'puppies'!) etc. And travelling with him now that he's 2 and got heaps more words and can walk greater distances by himself would be interesting, too - really, I think any age is great once you remove the preconceptions and the complications!
we took DS 1 and two OS when they were 3yrs and 6 months respectively. By the time we came back we worked out that DS2 had been on over 20 flights (domestic and internationally) by the time he was 7 months old - (they weren't all from this one trip though). With the OS trip we went to Hawaii and Canada - total time of almost 4 weeks. My DH still managed to read about 4 books in this trip (2 of which were on the flights)
We are looking at taking whole family to USA/Canada next christmas, they will be 6, 3 and 18mths respectively - some say we are gluttens for punishment. The worst bit for us will be how to balance the luggage. Poor DH usually gets caught lugging most of it.
It just depends if you want them to remember it or not. I don't remember any of the holidays my parents took us on before about 6 or 7. We went on family friendly holidays like to New Zealand, Bali or on South Pacific cruises when we were kids - great trips for families.
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