This book has an old-fashioned feel with plenty of bonuses like letters, pop-ups and pull-outs (somewhat fragile!). It would appeal to anybody, boy or girl who likes the idea of exploring or camping.
I recommend 6 yrs and up because the extras allow a child to 'grow into it'. The layout is fun and fact-filled with a variety of appealing topics from getting ready to explore (suggested tool kit), past expeditions in the jungle, arctic, desert etc... and how to survive. The book appeals to the imagination.
Explorer - a Daring Guide for Young Adventurers would make a nice complement to the Daring Book for Girls or the Dangerous Book for Boys, though it stands on its own nicely.