Ralston Hall Mansion is situated on the campus of Notre Dame de Namur University, on the San Francisco Peninsula. The mansion has been built around the villa of Count , former owner of the estate. Taking three years to build, it was completed in 1867, when San Francisco's leaders and first citizens had large summer homes on the Peninsula, an integral part of San Francisco high society. Architect John Painter Gaynor, who later worked with Ralston on the Palace Hotel in San Francisco, is thought to have worked on it. Several of the design elements of Ralston Hall Mansion were copied in the design of the Palace.