2 nights in Nagano

Hi
I'm leaving to japan on 24th july, this is what i've planned.
25/7 stay at osaka for the tenjin matsuri
26/7 visit kyoto
28/7 visit tokyo
29/7 go to the fuji q highland and stay the night at kawagushigo
30-31/7 i have to stay at nagano for 2 nights. all i've planned is matsumoto castle and zenkoji temple. Is there any interesting place to visit nearby? Is the alpine route and shirakawago worth going visit for 1 day trip?
1/7 go back to tokyo
I already bought the JR pass. I am not sure that this plan is going to work. please comment and help me out.
Thank you.

Nagano has a castle, railway park/museum, or head to Meiji Mura outdoor musuem. You could also day trip to Hikone, or up the Kiso valley to Takayama by train.

JapanCustomTours,

Do you mean Nagoya, not Nagano?

How about Matsushiro? (not to be confused with Matsumoto!) It's a suburb of Nagano which has a number of preserved samurai houses, the Sanada Treasure Museum, and a WW2 bunker: http://www.japanvisitor.com/japan-city-guides/matsushiro-guide

To get there you take bus #30 from bus stand #3 at Nagano station. Its about a 30 min bus ride.

Other things to see nearby are the snow monkeys at Yamanouchi: http://japan-guide.com/e/e6025.html

And Obuse: http://japan-guide.com/e/e6020.html

Thank you all for the comments. =)
I'm staying in Nagano, at the metropolitan nagano hotel.
Isn't it matsumoto castle that famous in nagano? maybe i'm confused.

I'm interested in the alpine route but i've learned that the snow corridor won't be opened the day i go. Is there any other place to visit in the alpine route or is wont worth it?

I'm interested in the alpine route but i've learned that the snow corridor won't be opened the day i go.

The hight of snow corridor decreases after it is opened in April, but in the end of July it still resides and of course is opened. You can see how it is like from a Tripadvisor page.

http://goo.gl/JLmmk0

Since you are from tropical country and you have a JR pass, I recommend you to try the Alpine route. You should reserve cable cars etc via WEB reservation system.

https://tateyama.kurobe.alpen-route.com/ticket/en/start.html

You should learn about the Alpine route in advance.

http://www.japan-guide.com/e/e7550.html