The Goryokaku fortress was built in Hakodate to protect the southern shores of the island of Hokkaido from foreign, primarily from the Russian ships. This fortification has not survived, but in its place was a Park, which, when viewed from a bird's eye view, follows the shape of the Fort is a five-pointed star.

Pentagonal Fort was built from 1857 to 1864 years. Construction was led by Takeda Naraki, independently studied the nuances of the construction of fortifications on the books, imported from Holland. Therefore, the Goryokaku fortress became the first and largest in Japan, is built on the principle of a European Bastion fortifications. The shape of the fortress in the form of stars allowed to bombard the enemy without "dead zones". The height of the wall was 5 meters of the wall was a ditch with water and earth mound. From the South-West side was built and a Ravelin is a triangular Fort in front of the moat between the two beams. In the fortress there were 30 buildings and an observation tower.

Thanks to the fortifications and gun to the Arsenal of the fortress of Goryokaku Hakodate harbour was included in the list of ports open to foreign merchant vessels under Kangaskokko Treaty signed by the Japanese government and the American Commodore Matthew Perry in 1854.

Despite the presence of such a formidable Bastion, since 1859 the Russian ships of the Pacific fleet used the Harbor of Hakodate as winter Parking and repair facilities.

In 1869, Fort Goryokaku became the site of a fierce battle between Imperial forces and the supporters of the Republic of yezo. During the assault, most of the buildings of the fortress and the tower were damaged.

City Park, the fortress began in 1914, in 1952, this place was included in the list of special historical monuments. Currently on the territory of the former pentagonal Fort has a branch Hakodate Museum and the Museum-Arsenal.