Whenever I watch national broadcaster NHK's weather forecast, I feel consoled that no matter how hot it may get in July and August in Tokyo, the mercury in Utsunomiya is always going to be several degrees higher.

So this city of 500,000 that's 100 km north of Tokyo in Tochigi Prefecture was the last place I expected to go to cool off — until I discovered the Oya Stone Museum, an underground limestone quarry where the thermometer registers about 8 degrees year-round.

I'd been to Utsunomiya a few times before; but normally just en route to more storied destinations in Nikko, 35 km to the west, such as the Toshogu Shrine, Kinugawa hot-springs resort or Nikko Edo Mura, a wonderfully managed historical theme park. Last month, though, I decided it was time to properly acquaint myself with the city itself.