Open park with grassy areas and a few trees at Sønderborg Castle, beautifully situated by the Als Sund strait. Sønderborg Castle and its park are owned by the Agency for Culture and Palaces.
The park's paths lead around Sønderborg Castle and out to the castle quay and the beach promenade, which takes you along Gendarmstien to the town's marina and further along the coast to the nearby forest area, Sønderskoven Als.