Heidelberg University is a private liberal arts college located in the city of Tiffin, Ohio in the U.S. state of Ohio. Founded in 1850, it was known as Heidelberg College until 1889 and from 1926 to 2009. Heidelberg University was founded by the German Reformed Church in 1850 and is currently affiliated with the United Church of Christ. At that time, there was a significant number of German immigrants in Ohio, and the German Reformed Church had seventy-four churches in the state when members decided to establish the college. The College had an initial graduating class of five students. Heidelberg is situated on 110 acres (0.45 km) enclosed in Tiffin, Ohio, the county seat of Seneca County, in northwestern Ohio. The campus is located on the east side of Tiffin on College Hill, within a half mile of downtown Tiffin. Heidelberg's campus includes 26 buildings, 10 of which are listed on the National Register of Historic Places. The architecture ranges from pure Greek Revival and Victorian Gothic to English Gothic and the functional style.