The Guatemalan ancient city of Piedras Negras, with its magnificent palaces, temples and other great buildings, was once the capital of a large Maya kingdom, reaching its apogee between c.450 and 810 AD. During the 1930s the University of Pennsylvania Museum, mostly under Linton Satterthwaite, conducted extensive excavations of the monumental buildings in order to uncover the chronology of the construction. This book reprints the original preliminary papers from the project which were never circulated to more than a few people and only a handful of copies survive today. The papers, all but one by Satterthwaite, report on the excavation of the ball courts, the palace structures, the pyramid, temples, sweathouses and unclassified buildings. A paper by Mary Butler focuses on the pottery. The editors of this volume introduce the papers with a discussion of the project and a history of its publication.