Saco (pronounced /ˈsɑkoʊ/, SAH-koh) is a city in York County, Maine, United States. The population was 16,822 at the 2000 census. It is home to Ferry Beach State Park, Funtown Splashtown USA, Thornton Academy, as well as General Dynamics Armament Systems (also known by its former name, Saco Defense), a subsidiary of the defense contractor General Dynamics. Saco has two growing business parks and another one under development. Saco sees much tourism during summer months, due to its amusement parks, Ferry Beach State Park, and proximity to Old Orchard Beach. Saco has taken steps to make the city more environmentally friendly. In early 2007 a wind turbine was erected near the water treatment plant at the foot of Front street. Another wind turbine was erected on the top of York Hill in December 2007 to generate power for the new train station for Amtrak's "Downeaster. " This is part of the project to restore Factory Island, including the renovation of several abandoned mills that have fallen into disrepair, and the erection of new townhouses and a marina. Saco is part of the Portland–South Portland–Biddeford, Maine Metropolitan Statistical Area. Saco's twin-city is Biddeford.