The purpose of this cultural landscape report is to thoroughly examine and document the physical development of the thirty-acre portion of the Charlestown Navy Yard that is owned and managed by the National Park Service. The report describes the evolution of the landscape from its establishment as a navy yard in 1800 until its closure in 1974 as well as changes during the period of National Park Service (NPS) management from 1974 to present. This site history is followed by a description of the current condition of the property and an analysis of historical significance and integrity. This includes an evaluation of the yard's historic and contemporary landscape characteristics, such as changes in spatial organization, circulation, and vegetation. With an understanding of the historical fabric, the report then presents treatment issues and recommendations related to security, accessibility, paved surfaces, trees, lawn areas, lighting, and other site features.