Chuson-ji Temple
Chuson-ji Temple, founded in 850 AD, owns over 3,000 national treasures and important cultural properties and is also registered as a World Heritage site. This temple was built to transmit the powerful wish to comfort the spirits of those killed in the Tohoku War, no matter which side they were on.
The architecture is beautiful, and the natural surroundings are lovely too.
There's also a fantastic soba noodle restaurant nearby—definitely worth checking out while you're here.