Mercer County Ohio (Vacant / Not In Use) has 1 places on the National Register of Historic Places.
Some of the country's most noteable architects helped create the Mercer County places including Hulsken & Strong. Prominent architectural styles found in Mercer Country are Prairie School.
Otis Hospital
(added 1980 - #80003160)
441 E. Market St. , https://npgallery.nps.gov/AssetDetail/NRIS/80003160