Southeast is the second largest town in Putnam County. The town has a total area of 35 square miles and a population over 17,000. Southeast was founded in 1788, and is located at the crossroads of Interstate highways Route 684 and Route 84, and State Routes 22, 312, 6 and 202. Metro-North Railroad's Harlem Line has two stops that service the area. The town is home to a number of designated historic sites, including the Old Southeast Church and Old Doansburg Schoolhouse, Old Town Hall, and the Walter Brewster House. In addition to numerous homes and sites of historic interest from the 18th and 19th centuries, Southeast also boasts the Milltown Area and Starr Ridge historic districts.