I flew my baby overseas at 4th months old and at 7th months old. We brought her to malls, library, aquarium, and zoos in Thailand. Whereas in Singapore, we brought her to Aquraium, parks and malls regularly.
But ultimately, baby is happy with you as long as you are around them. Where you bring them, at home, park or mall, most importantly is that you spend quality time with them.
Elene