The Montgomery County Courthouse (MCC), built in 1847, is an historic Greek Revival building located on the northwest corner of Third and Main streets in Dayton, Ohio. It is referred to locally as the Old Courthouse. The limestone building, modeled on the 5th century BC Temple of Hephaestus in Athens, Greece, is the nation’s best surviving example of a Greek Revival style courthouse. The Courthouse was added to the National Register of Historic Places on January 26, 1970.