Shiga Highlands & Jigokudani Monkey Park
A few kilometres east of Nagano is Japan's largest ski resort, Shiga Kogen (志賀高原 or "Shiga Highlands"), in the municipality of Yamanouchi. This is where the skiing events of the Nagano Olympics took place. There are 21 slopes and 71 lifts.
Even if you are not skiing the place is well worth a visit for the Jigokudani Monkey Park (地獄谷野猿公苑 ; 'Jigokudani' means "Hell Valley"), where the wild Japanese Snow Monkeys can often be spotted bathing in the local onsen (hot springs). There are some 200 wild monkeys in the park, fed by the guardians. The macaques are accustomed to human presence and relax nonchanlantly in the warm bath or play in front of the visitors (touching or feeding them is prohibited though). Jigokudani is in the village of Kanbayashi, on the road from Obuse to Mount Shiga. The nearest train station is Yudanaka, the last stop on the Nagaden (Nagano Dentestu) railway. From there you can either catch a taxi or walk the 2 mk along the main road.
Watching monkeys is one thing, but the pleasures of thermal springs relaxation are not offlimits to human beings, and quite a few ryokan hotels offer all one needs to enjoy the geothermally heated waters. The town of Yudanaka offers a wide range of possibilities such as Hotel Tsubakino, Iwanoyu Ryokan at Seni Onsen, Kōrakukan Minshuku and Seifuso at Jigokudani Onsen, Senjukaku Ryokan at Kanbayashi Onsen, Kanaguya Ryokan and Shibu Hotel at Shibu Onsen. There are other options closer to the ski slopes in Yamanouchi, like the Kokuya Ryokan or the Shiga Kogen Prince Hotel.
Hokusai Museum in Obuse
The small town of Obuse, 15 km north-east of Nagano, is home to the Hokusai Museum (北斎館). Katsushika Hokusai, the great ukiyoe artist, lived in Nagano for the last 6 years of his life, from 1842 to 1849. Apart from the usual woodblock paintings, the museum also exhibits some mikoshi with ceilings painted by Hokusai.
You can get there by train from Nagano station, alighting at Ofuse (20 to 30 minutes). It's roughly 10 minutes' walk south-east from Ofuse station to the museum (check the way on Google Maps).
Map of attractions in Nagano