Book excerpt: The topic of site characterization is unique to geotechnical engineering and owes its significance directly to the variability of the natural geologic deposits on the earth’s surface. Proper site characterization requires an understanding of various field and laboratory investigation methods. The book discusses the suitability of various methods under different site conditions and presents the procedures to derive design parameters based on interpretation of test results. Recent developments in specialized site characterization methods (such as seismic hazard evaluation) are also included. Three recent case histories are presented, where site characterization played a key role. The three disparate cases include soft natural soil under static loading, coarse and fine-grained soil under seismic impact, and hazardous waste deposits under both static and seismic loading. Site investigation requirements of building codes are discussed and guidelines for preparing a typical site characterization report are presented. The book is aimed at the practicing geotechnical engineer, as well as advanced undergraduate and graduate students.