Planting Trees The illustrations in early copies of Marco Polo’s book show the elements that Europeans found most interesting. This page illustrates Khubilai’s order that trees be planted along the main roads. (Illumination fromLe Livre des Merveilles du Monde [Travels of Marco Polo], by the Paris studio of the Boucicaut Master, c. 1412/Bibliothèque Nationale, Paris/akg-