Kosetsuen is a National Cultural Heritage Garden within Miharashi Koen Park in Hakodate City, Hokkaido. It is a Japanese teien garden originally made as a villa for a wealthy merchant and there are many things to see there, including a brickwork greenhouse and a garden pavilion built in the traditional shoin-zukuri architectural style. About 150 species of garden trees grow within the park, and the gardens change color with the seasons: pink cherry blossoms in spring and red maple trees in autumn. The park is known as a famous place for viewing autumn leaves, and during the season for the changing autumn colors illumination events are held.