The discovery in 1995 that a long-ignored doorway in the Valley of the Kings was actually the entrance to the largest tomb ever found in Egypt made headlines around the world. Called KV 5, it contains over 150 corridors and chambers, and was used as a family mausoleum for several sons of the New Kingdom pharaoh, Ramesses II. This preliminary report is the first comprehensive, technical publication on the work of the Theban Mapping Project in the tomb. It includes detailed archaeological and architectural studies, epigraphic surveys, object and pottery descriptions, discussions of conservation work, and extensive reports on the site's geology, hydrology, mineralogy, and geotechnical engineering. Copiously illustrated with photographs and line drawings, KV 5 is the essential source for the study of this fascinating and important tomb.