Tenkyōkaku
This villa was built in August 1908 during Prince Arisugawa Takehito’s travels through the Tohoku region, after he was captivated by the beauty of Lake Inawashiro. When Crown Prince Yoshihito (later Emperor Taishō) visited the following September, it is said that the villa was named Tenkyōkaku after a line in a poem by Li Bai: “The bright lake reflects the heavens like a mirror” (Ming hu luo tianjing). As a former imperial villa, it is the northernmost of its kind in Japan and was designated a National Important Cultural Property in 1979.
There’s an audio guide inside that’s worth listening to. It really helps you appreciate the history of this building.