The entire book is illustrated in a watercolor style that feels soft.
Tredition Verlag
Elbow-Room
Even the margins are illustrated with small decorative motifs.
Les Derniers Peaux-Rouges Le Tr?Sor De Montcalm
The book is illustrated in a way that appeals to both kids and adults.
Oz
A nice touch in this activity book is the bonus content accessible online.