新発田藩領・蓮潟興野の名主職の家柄で、大地主だった二宮家の庭園です。現在の9代目当主夫人が20余年かけて育てた約300種500株が植えられた壮大なバラ園や、クレマチス、オルレアなど様々な草花で彩られたイングリッシュ風ガーデンは圧巻です。冬に白鳥が飛来する弁天潟を借景とした日本庭園「静勝園」や、120年を超える松や楠、国の登録有形文化財の主屋（内部は非公開）などもあります。

　This garden belonged to the Ninomiya Family, a large landowner whose ancestry traced back to Hasugata Kono, a famous leader of the Shibata fief. The magnificent rose garden, which boasts 500 plants from 300 species grown over the past 20 years by the wife of the current ninth-generation owner, as well as the English-style garden colorfully blooming with a variety of flowers such as clematises and orlayas are masterpieces. Also of interest are the Seisho-en Japanese-style garden overlooking Benten-gata (a marsh to which swans migrate during winter), pine and camphor trees that are more than 120 years old, and the main building, which is designated as a national Tangible Cultural Property (inside not open to the public).