We travel a ton and we found that including our kids is key to keeping them happy as we tote them around the world. We found a series of books that are great and I highly recommend. They are Mission: (enter city here) books and they can be found on Amazon. They have some of the major cities in Europe ( Barcelona, Rome, Florence, London, Paris, Amsteradm) and a couple in the states. It's basically a scavenger hunt book for kids, but it points out some really cool stuff that we would not have noticed otherwise. It also throws in some secret history lessons so they are learning as they go. They can then go online and print out a certificate if they get enough points. My kids love these books and we have used almost every single one that is available!.