The Old Towne, Orange Historic District, also known as Downtown Orange and colloquially as The Circle, is a one-square-mile district centered around Plaza Park in Orange, California. The district contains many of the original structures built following the city's incorporation and includes Orange County's oldest operating bank. Listed on the National Register of Historic Places in 1997, it is the largest National Register District in California. The Old Towne Preservation Association is a non-profit organization dedicated to maintaining the district.