Alde Feanen National Park is a national park in the Netherlands province of Friesland. The Alde Faenen is also a Natura 2000 area. The Alde Feanen is part of the communities Boornsterhem, Smallingerland and Tietjerksteradeel. Its size is about 25 km2 (9.7 sq mi). Part of the national park is the lake area Princenhof (or Princehof). The Alde Feanen contains morasses, lakes, forests, peat and meadows. In the area at least 450 plant species and 100 bird species can be found.