For centuries, poets and philosophers extolled the benefits of a walk in the woods: Beethoven drew inspiration from rocks and trees; Wordsworth composed while tromping over the heath; and Nikola Tesla conceived the electric motor while visiting a park. Intrigued by our storied renewal in the natural world, Florence Williams set out to uncover the science behind nature's positive effects on the brain.

In this informative and entertaining account, Williams investigates cutting-edge research as she travels to fragrant cypress forests in Korea to meet the rangers who administer "forest...