The McElroy Octagon House is located on Gough Street in the Cow Hollow section of San Francisco, California. It is one of only three octagon houses remaining in the city. The home was built in 1861 for William, a local miller, and Harriet McElroy in the then-popular octagonal style. William died in 1869 and Harriet in 1899. The home was inherited by their daughter, Emma Eliza, who lived here until her death in 1909. Since then the home has changed hands several times, most notable was it's purchase by the Pacific Gas & Electric, who owned the property until 1952. By that time the home had seen better times. It was initially severely damaged in the 1906 earthquake. From 1949 on the house stood vacant and deteriorating, at which time PG&E were looking to sell the land and destroy the house. Two ladies who were members of The National Society of The Colonial Dames of America in California happened to live across the street from the home and offered to donate land for the building. The group was looking for a historic home to serve as their museum. In 1952 the house was moved across the street to it's new location, completely renovated and restored. It was during these renovations that a time capsule was discovered, placed by the McElroys, which contained documents that helped track down the history of the home, including when it was built and who lived here. the Octagon House was added to the National Register of Historic Places in 1972. It now serves as a museum.