All across the world, trees play a role in every part of human life, offering sanctuary and inspiration, not to mention the raw materials for everything from aspirin to maple syrup. Combining botany, history, and anecdotes, former BBC documentarian Jonathan Drori proves the point here, visiting the lime trees of Berlin's Unter den Linden boulevard, which intoxicate amorous Germans and hungry bees alike; the swankiest streets in 19th-century London, which were paved with Australian eucalyptus wood; and the redwood forests of California, where he reveals the secret to the trees' soaring heights.