本书对古代园林建筑知识的介绍。包括四合院有多大？为什么现在越来越少；万里长城真的有一万里长吗？(This book introduces ancient Chinese gardens and architecture, like what is the floor area of a typical quadrangle courtyard? Why are there fewer quadrangle courtyards now? Is the Great Wall really as long as ten thousand li (500 meter)?)