is a nature park located in Tsukigata Town. Within the park, there is an observatory from which one can view the entire town of Tsukigata and the "Northernmost Cedar Forest in Japan" planted in 1890 by the prisoners of Karafuto Shuji Jigyo (Karafuto Shuji Jigyo).
There is also a monument commemorating successive generations of prisoners and the site of the reference point for the opening of the Horonobe Road.
The park is decorated with cherry blossoms in the spring and autumn leaves in the fall.

Cedar forest in Maruyama Park.
About 600 cedar trees were planted by prisoners in 1890 to commemorate the 10th anniversary of the Karafuto Shuji Jigokan (Karafuto prison).
It is said that the prisoners took great pains to care for the trees out of a sense of nostalgia.
It is the northern limit of cedar trees planted in Japan and is designated as a protected plant community forest.