This is the 2056th most frequent Japanese word.
信州
"信州" refers to the historical name for the Nagano Prefecture region in Japan.
'信州' refers to a geographical region in Japan, known for its natural beauty and scenic landscapes. The word is used as a proper noun.
信州は紅葉が美しい地域です。
Shinshu is a region where autumn leaves are beautiful.
'信州' is used here to indicate the destination of the speaker's travel, again as a proper noun referring to the region.
私は去年、信州に旅行しました。
I traveled to Shinshu last year.
'信州' contextualizes the variety of 'soba', a popular Japanese noodle dish, indicating that it originates from or is associated with the Shinshu region.