Plön is famous for its lakes, which essentially surround the city. There is a 17th century mansion "castle" on a hill at the center of the city. The old and charming little Johanneskirche church is worth a visit as well as the Parnassturm tower, which offers a scenic view of the city with its surrounding landscape and lakes. There are also good walking trails and a hike to "Prince's Island" is a scenic day walk. Another interesting work is around the Trammersee lake to the cities north. Through the 2h walk, you will pass through small villages, forests and scenic landscapes.