Located on the corner of Gough and Union Streets, Octagon House was built in 1861 by William C. McElroy, a miller and early resident of San Francisco. This unique architectural style was popular in the mid-19th century. The octagonal shape was thought to contribute to healthful living by providing more interior light and air circulation in the home. At one time there were at least 5 other octagonal residences in San Francisco.
Octagon House is owned and maintained by The National Society of The Colonial Dames of America in California.
It is open to the public as a house museum showcasing early American and Federal furniture, paintings and decorative arts.
Visitors to Union St. are invited to tour the museum and garden.