{"nrhp_refnum":"74001430","name":"Gwinn Estate","other_names":["William G. Mather House"],"category":"building","location":{"address":"12407 Lake Shore Blvd.","address_restricted":false,"city":"Bratenahl","county":"Cuyahoga County","state":"OH","lat":41.56017600800004,"lon":-81.59921430999998,"geom_source":"nps_gis"},"listed_date":"1974-10-01","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Industry","Landscape Architecture","Architecture","Social History"],"significance_levels":["state"],"summary":{"what_it_is":"A six-acre lakefront estate at 12407 Lake Shore Boulevard in Bratenahl, Ohio, centered on a two-story Italian palazzo-style mansion built in 1907-1908 as the residence of William G. Mather.","why_significant":"The nomination argues the house has dual significance: it was the home of William G. Mather, a leading Cleveland industrial and civic figure, and it is the most complete expression of the Renaissance ideal in the area. Its design and grounds approximate sixteenth-century Medici palaces and villas. The architect was Charles A. Platt of New York, with landscape design by Warren Manning.","narrative":"Gwinn Estate is a six-acre property on the shore of Lake Erie in Bratenahl, Ohio, built in 1907-1908 for industrialist William G. Mather. Its mansion is a rectangular two-story Italian palazzo in the Second Renaissance Revival style, with stucco walls, a flat cornice and a balustraded roof. The north front faces the lake, with a two-story semicircular Ionic portico, terraced stairs to the beach, a fountain, a curving concrete retaining wall and a columned gazebo. Formal gardens on the south side follow a sixteenth-century layout. Inside, the library is fully panelled in walnut. Mather led the Cleveland-Cliffs Iron Company and served the Cleveland Museum of Art and several educational and medical institutions. New York architect Charles A. Platt designed the house to evoke Medici palaces such as the Palazzo Pitti and Villa d'Este, and Warren Manning planned the landscape. The house remains virtually unaltered and is valued as a complete local expression of Renaissance ideals.","period_of_significance":"20th Century (specific date 1908)","architect_builder":"Charles A. Platt of New York (architect); Warren Manning (landscape design)","architectural_style":"Second Renaissance Revival; Italian palazzo","criteria":[],"status_note":"Listed in excellent condition, unaltered and on its original site; the form notes it houses a collection of paintings and art objects and is maintained, with the formal garden described as well maintained.","vacant_flag":null,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:53:10.28938-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_OH/74001430.pdf"},"photo":null,"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/71987719","wikipedia":null,"wikidata":"https://www.wikidata.org/wiki/Q137641636"},"indexable":true,"url":"https://nationalhistoricalregister.com/ohio/cuyahoga-county/gwinn-estate-74001430/"}