My son was 3 months the first time we went, and then 18 months the next time, then 34 months. and I packed him a diaper bag. He was on formula at 3 months so I just brought his forumla and a few bottles of room temp water, i think two changes of clothes, and diapers and wipes. Second trip, a few change of clothes and juice and diapers and wipes. this last time, snacks, juice, water, clothes, and wipes. I think as long as I get to go while my kids are still little, the wipes will be a staple....and a change of clothes cause they like to play in the fountains and you never know when they will spill something on themselves.