We love to travel and even though we aren't going trans atlantic with our kids until they are old enough to ... well not sure what milestone , but I know we aren't ready yet. What we are ready for is to explore geography through games. This is a simple game that gives kids a chance to play with a globe or map and make their own decisions about mode of travel.
Grab a piece of paper and write down some destinations , some close to home and some further away, We live outside Seattle so I had Vancouver BC, Portland, and San Francisco as my close destinations. For the further away ones were : China, Australia, India, England and Paris . I mixed up countries and cities so it gave us a chance to talk about the difference on the map.
Now find each place and decide ... should you take a plane , a boat or a car?
Ask why.. and don't spend too long explaining why your child is wrong if they suggest a car to get to Australia, ask them how a car would get there... they might have an explanation up their sleeve!