Travel light, buy what you need along the way. Take long flights during the night so they'll sleep. Take trains/subways instead of cars/taxis as they'll be able

Travel light, buy what you need along the way. Take long flights during the night so they'll sleep. Take trains/subways instead of cars/taxis as they'll be able to walk around and interact with other people. Mix activities for adults with thing that they would enjoy (zoo, parks, fireworks, ...). Hype up some of the things they'll see the next days so they'll be excited to see it. Let them pick some of the restaurants and activities.