The Glensheen the Historic Congdon Estate is a mansion in Duluth, Minnesota, United States, operated by the University of Minnesota Duluth as a historic house museum. Glensheen sits on 7.6 acres (3.1 ha) of waterfront property on Lake Superior, has 39 rooms and is built in the Jacobean architectural tradition, inspired by the Beaux-Arts styles of the era. The mansion was constructed as the family home of Chester Adgate Congdon. The building was designed by Minnesota architect Clarence H. Johnston Sr., with interiors designed by William French and the formal terraced garden and English style landscape designed by the Charles Wellford Leavitt firm out of New York. Construction began in 1905, and completed in 1908.