We will be traveling to London in June with two 13 year olds. I think our best option for the tube is to purchase one day Family Travelcards. For zones 1 and 2 it is 3.10 pounds per adult and .80 pounds for each child. That is only good for zones 1 and 2 and I'm not sure about time restrictions. Am I correct in thinking this is our best option or is there something better out there?? Thanks.