Heilbronn is a city on the Neckar River in southwest Germany. St. Kilian Church dates back to the 13th century, with an octagonal Renaissance tower and a Gothic altarpiece. The Town Hall facade has a 16th-century astronomical clock. North in the Neckar Valley, the late-medieval Guttenberg Castle has a museum and live birds of prey. East of the city, the area around Lake Breitenau has trails and vineyards.