The Kozjansko nature park is one of the oldest and largest protected areas in Slovenia. It stretches into the Posavje Region, the region along the Sotla river and the region of Kozjansko. The northern, hilly part of the municipality of Brežice is part of this park with an extraordinary biotic diversity, as well as numerous activities for the preservation of long-term sustainability. One of the most recognizable activities for the sustainability of the region are the fruit-gardens with old fruit-orchards of old resistant sorts of fruit. The Kozjanski park is also actively involved in all sustainability-related activities in the region. Information on the park and its activities is available in the castle of Podsreda.