Arboretum Opeka is the only existing arboretum in continental Croatia. It is one of the most significant arboretums in the country. It is located in a small place called Marčan, in the municipality of Vinica, about twenty kilometers northwest from Varaždin. It has over 100,000 copies of trees, shrubs, plants and flowers. The arboretum is influenced by the variety of plants and trees. It covers an area of about 30 hectares, and is divided into two parts - a park that is available to visitors and to the forest that occupies most of the area. It belongs to the English style.parks. In addition, there is a famous castle, which, unfortunately, is now in ruinous condition. Vandalism and ignorance are the main culprits of such a state. The castle was built by Nikola Keglević from Buzina in 1674 for himself and his successors. After his death the castle has experienced many changes. The arboretum began to be formed in the 19th century. Count Marko Bombelles junior had a big influence on the curent apperance. He brought different plant species from his travels and fitted them into the park. In addition to plant diversity, in the park we can see the lake, an empty pool, a ruinous servant house and more. The whole arboretum came into state ownership in the sequence of circumstances and the arboretum care was neglected. That is why today, as mentioned above, the castle is in a ruinous state, and the plants and trees are decaying. Nevertheless, the arboretum has retained its charm and still attracts people's attention.