My four-year-old has two favorite trees. She absolutely loves gingkos, and are fascinated by their fan-shaped leaves. The other is "The Elephant Tree" as she calls it. This Fagus sylvatica (Copper Beech) is located near the Morton Arboretum's Visitor Center and always captures my little girl's attention, especially this fall.
Fagus sylvatica is a purple-leafed beech that exhibits incredible coppery fall color. Old trees, like the one pictured, develop beautiful grey elephant-skin bark. Because this tree gets so big (70-80ft), and branches so closely to the ground, it is usually not appropriate for the residential landscape, unless you've got a lot of property. If you do, this tree is one of the finest trees available for a large-scale landscape.