With an excellent architectural design that combines Japanese and Western elements, and with the well-preserved furniture in the building, the two-story wooden main building was designated an Important Cultural Property in 1974 (Showa 49), and the annex building that serves as the caretaker's office was designated an Important Cultural Property in 1980 (Showa 55). It is a historic building that represents Hakodate. It was reopened on April 26, 2021.

The overall exterior is impressive, but if you look closely at the details, you'll see that the dormer windows, ridge fences, pediments, columns, capitals, and other details are all very stylish. The VIP room on the second floor, which has actually been used by members of the imperial family, is particularly eye-catching, with its imported wallpaper, chandeliers, fireplace, and other interior dignified ambience.

In addition to the extensive exhibits inside the building that explain the history of the public hall and the characteristics of the building, the Costume Museum is also popular, where you can experience a foreign atmosphere by trying on gorgeous long dresses and high-collar outfits. Why not try on your favorite outfit and immerse yourself in an elegant atmosphere while overlooking the harbor from the balcony on the second floor? Inside the building, there is also a shop selling products that are typical of Hakodate, so it is also recommended to look for souvenirs.