There are 343 properties and districts listed on the National Register in Hamilton County, including 14 National Historic Landmarks. The city of Cincinnati is the location of 251 of these properties and districts, including 12 National Historic Landmarks; they are listed here, while the remaining 92 properties and districts, including 2 National Historic Landmarks, are listed separately.
The properties are distributed across all parts of Cincinnati. For the purposes of this list, the city is split into four regions: Downtown Cincinnati, which includes all of the city south of Central Parkway, west of Interstates 71 and 471, and east of Interstate 75; Northern Cincinnati, which includes all of the city north of a line running along Interstate 74 from the city's western edge to Interstate 75, south to Martin Luther King Drive, east to Interstate 71, and north to the city's eastern edge; Eastern Cincinnati, which includes all of the city outside Downtown and Northern Cincinnati and east of Vine Street; and Western Cincinnati, which includes all of the city outside Downtown and Northern Cincinnati and west of Vine Street. One district, the Over-the-Rhine Historic District, is split between Eastern and Western Cincinnati.
^The latitude and longitude information provided in this table was derived originally from the National Register Information System, which has been found to be fairly accurate for about 99% of listings. For about 1% of NRIS original coordinates, experience has shown that one or both coordinates are typos or otherwise extremely far off; some corrections may have been made. A more subtle problem causes many locations to be off by up to 150 yards, depending on location in the country: most NRIS coordinates were derived from tracing out latitude and longitudes off of USGS topographical quadrant maps created under the North American Datum of 1927, which differs from the current, highly accurate WGS84 GPS system used by most on-line maps. Chicago is about right, but NRIS longitudes in Washington are higher by about 4.5 seconds, and are lower by about 2.0 seconds in Maine. Latitudes differ by about 1.0 second in Florida. Some locations in this table may have been corrected to current GPS standards.