Ironville Historic District is a national historic district located at Ironville in Essex County, New York. The district contains 12 contributing buildings. It encompasses the area associated with a once thriving iron works. Almost nothing remains of the iron works itself. The remaining buildings consists of modest wooden dwellings including the Penfield Homestead (1828; now a museum), boarding house (1827), Congregational Church (1842), commercial building / grange hall (1870s), and cemetery. Ironville is known as the "Birthplace of the Electrical Age", being the site of the first industrial application of electricity in the United States.