Ashinasawadate Castle Ruin is located on the hill between the Omonai River and the Kirita River to the northeast of Ashinasawa Village on Lake Towada. The castle area takes the shape of a triangle. The north compound used to stand at the apex of the triangle and the east and the west compounds stood on the both ends of the base line. Part of the ruin is reclaimed for farm land but the site as a whole is well-preserved. The remains of double structure moats can be seen clearly. The precise history of the castle is unknown but it is said that either Okuse clan or Hatakeyama clan resided in this castle. It is presumed that the castle as well as Sawadadate Castle functioned as one of the base camps to invade Tsugaru Province. There is a legend that gold ingots were dug out of this ruin.