Children learn from all the experiences you provide for them outside of school. The more positive and constructive learning experiences children have outside of school, the better they do in school.
There is probably no better time for you and your children to learn than when you're on vacation. Everyone is together, everyone is ready for an adventure, and, in many cases, everything is new.
Children can help you plan the trip. Check out library books or the Internet to gather information about what you will visit. Each child can investigate one aspect of the trip and report on it during the trip to the rest of the family. Or, for younger children, a parent can read about the area or site while riding in the car. They can help with other parts of planning-by figuring out a route or by making a list of things to pack.
Once you're on the trip, your children can serve as navigators and keep a trip log. Or try car games like "I spy with my little eye, something that starts with the letter . . ." To teach financial responsibility, you might want to give them an allowance for souvenirs, or gifts to bring to others.
Of course, you'll want to see, and talk about, some objects of interest like museums and zoos. Remember to plan some down time. Bring some books for rainy afternoons or break times. Have children buy postcards, so they can write to their friends or family back home.
Once you're back home, have the family put together a trip scrapbook. The trip may be over. But learning is just beginning.