Art Peterson has translated his lifelong love affair with his favorite city into a sparkling, well-researched guide, exploring San Francisco's quirks, landmarks and eccentricities. Why Is That Bridge Orange? links everyday sights that are the fabric of San Francisco with answers to nagging questions that tantalize the curious. Why is Lombard Street crooked? How does a cable car work? Why are there windmills at Ocean Beach? In 240 pages, 86 of these conundrums are resolved, supported by dozens of contemporary and historical photos. It all adds up to a crash course in urban discovery.