Yes, Nagano is wroth visiting in the winter. There are many places to visit in Nagano, including temples, shrines, and museums. There are lots of delicious and hearty foods, ideal for winter, like oyaki, sauce katsudon, or the shinshu miso ramen. Nagano in winter is a must if you love winter sports and the great outdoors, as the region boasts several world-class ski resorts such as Hakuba and Shiga Kogen.