O.J. Tinker donated the land for the Humboldt City Square Park in 1871. The bandstand in the center of the park was dedicated in 1912 in his memory. The park features a playground, Lions Club water fountain with memorial bricks, two American Legion Post #269 war memorials and stage that has hosted the Richardson County Fair since 1921. The Humboldt Commercial Historical District was placed on the National Historic Register in 2005. The Nebraska Historic marker is in the northeast corner of the City Park. Humboldt City Square features historic lighting, a mural illustrating the history and heritage of Humboldt and brick streets.