In 2012, federal agencies reported to the Federal Real Property Council (FRPC)--an organization comprised of all real property holding federal agencies--that they are responsible for operating over 480,000 federally owned structures. Information about these structures is recorded in the FRPC's Federal Real Property Profile (FRPP), the government's comprehensive database that describes the nature, use, and extent of federal real property. About 176,000 of those structures are operated by civilian federal agencies. The federal government manages a wide variety of structures. Some of these are common across agencies, such as roads and parking structures, while some are more specific to agencies' missions, such as historic structures or particle accelerators. This book examines the scale and scope of federally owned or leased structures; how federal agencies track and categorize federal structures; and the extent to which the challenges federal agencies face in managing buildings also apply to structures. This book also identifies actions agencies have taken to manage historic federal buildings; and any challenges they have faced.