The Marion County Courthouse is a handsome Beaux-Arts building completed in 1900 and listed on the National Register of Historic Places. Its stone facade, rounded corner tower, and ornamental detailing are the most architecturally distinguished elements of Fairmont's modest downtown. The building still serves its original function as the county courthouse.
It is worth a look from the outside while walking the Fairmont Downtown Historic District, which surrounds it. The district has a collection of late-19th and early-20th-century commercial buildings that give a clear picture of what a prosperous coal-country town looked like at its peak. The Masonic Temple on Adams Street is another notable building in the area.