Dewa Province was a province of Japan comprising modern-day Yamagata Prefecture and Akita Prefecture, except for the city of Kazuno and the town of Kosaka. Dewa bordered on Mutsu and Echigō Provinces. Its abbreviated form name was Ushū (羽州).

Taga Castle was a jōsaku-style Japanese castle built in the late Nara period in what is now part of the city of Tagajō in Miyagi prefecture in the Tōhoku region of far northern Honshu, Japan. Bashō tells of his visit to the site in Oku no Hosomichi. The ruins of Taga-jō and its former temple have been designated a Special Historic Site (特別史跡) since 1922.