Nagano is a city in Japan.
South towards Tokyo
Take the train from Nagano Station to Sakaki Station, from there it's a scenic 30 minute walk up a hill to a small P.A., with just a toilet building. You'll have to hop a small fence to reach it.
North towards Niigata
There is a P.A. for cars heading north opposite the one described above, but its use is unconfirmed.