Built in 1905, the Kosaka Mining Office is a cultural asset symbolizing the heyday of Kosaka Mining that once had the highest production in the country. The building itself is highly valued with its Renaissance-style exterior and artistic design of its interior, including the spiral staircase in the entrance hall. The current office was relocated and restored mainly with original materials and specifications in April 2001.
The Korakukan was built as a recreation facility for the Kosaka miners in 1910. It is a significant building in Japan as its exterior was designed in an elaborate Western-style while its inside looks like a typical late 19th-century theatre with traditional kabuki features, such as sajiki, a ground tier, hanamichi, an extended pathway through the audience and suppon, a trapdoor located on the walkway--a blending of Japanese and Western style. Even today, the theatre, now a national important cultural asset, attracts and entertains many people with its regular programs and kabuki performed by some of the top actors.
Kosaka, Kazuno-gun, Akita / Kosaka Mine Hospital started as Kosaka Mine Clinic in 1899. As the number of Kosaka Mine's employees increased the clinic upgraded its infrastructure and in 1908 reopened as the first general hospital in Akita. The Old Kosaka Mine Hospital Memorial Building was constructed as a mortuary of the hospital then. The building was designated as a national tangible cultural asset.