New to the city, Tallmadge saw only its concrete, glass, smog, and debris. Soon his interest, stirred by the wonder of his children at their new surroundings, focused Tallmadge to the ""buzzing, flapping, scurrying, chewing, photosynthesizing life forms"" around him. More deeply, Tallmadge began to learn from, and not just about, the city. Nature's persistence - within him and wherever he looked - wore away at old notions of wilderness that made no allowances for human culture. The ""arch"" of the book's title is richly resonant: as the name of a geologic formation molding the urban landscape Tallmadge comes to love; as an archetypal building form; and, in its parabolic shape, as a metaphor for life's journey. Filled with luminous lessons of mindfulness, attentiveness, and other spiritual practices, this is a hopeful guide to finding nature and balance in unlikely places.