The National Park Service, through its Cultural Resources Division, oversees the conservation of historic properties throughout the country. They have identified four potential treatment approaches and the standards that apply to each. These approaches are Preservation, Rehabilitation, Restoration, and Reconstruction. This lecture will give examples of each treatment approach in the United States as well as in Europe, including the Detroit Opera House and Michigan Central Train Station, Colonial Williamsburg in Virginia, and Notre Dame Cathedral in Paris as well as a number of others.