The former Indiana County Courthouse, now a bank headquarters (see also IN3), is a red brick, four-and-one-half-story Second Empire building with a mansard roof, pedimented window surrounds, and Corinthian columns, with cast-iron capitals surrounding the heavily proportioned square clock tower.

When the new courthouse was built and this one slated for demolition, NBOC leased the building from the county for ninety-nine years. Renovations by Millan Kerr Architects earned the Excellence in Design-Extended Use award in 1977 from the Pittsburgh chapter of the American Institute of Architects. Opposite, at 600 Philadelphia Street, is the large, limestone-clad First Commonwealth Bank (originally First National Bank) of 1934, with handsome Art Deco touches and a classically ornamented interior. These two buildings are the architectural highlights of the borough's main street.