The Oya History Museum is Utsunomiya's most memorable sight. The old quarry chambers open into more than 20,000 square metres of cool underground space, with stone walls rising like the inside of a buried cathedral. Exhibits explain how Oya stone was cut and used, but the real pleasure is simply walking through the carved caverns.
Bring a layer even in summer, since the temperature drops sharply underground. The museum is about 30 minutes by bus from Utsunomiya Station, and combines well with Oya Temple and the Peace Kannon nearby.