Gavnø Castle sits on a small island just south of Næstved, connected to the mainland by a short causeway. The current Baroque building dates from the 1740s and houses one of the largest private painting collections in Scandinavia — over 1,500 works covering European art from the 15th to 20th centuries. It is the main cultural attraction in the area around Næstved.
The castle gardens are spectacular in spring and early summer, with one of Denmark's most impressive tulip displays and later a rose garden. The estate is privately owned but open to visitors during the summer season. Combined visits to the house, collections, and gardens are available.