Description:Spanish Colonial missions and Mexican rancho and pueblo adobe structures are among California's earliest existing structures and the only above-ground remains of the state's original settlement by the Spanish and Mexican people. The Northridge earthquake brought about tragic losses to a number of these historic buildings. It also provided a rare opportunity to assess the damage that can occur as the result of a large earthquake. As part of the Getty Conservation Institute's commitment to researching conservation measures for adobe structures, this study surveys the damage to the buildings and evaluates their seismic performance. The ultimate goal is to use the lessons learned from this earthquake and the retrofit research to help understand and so limit the risks earthquakes pose to these treasures in the future.