Gifu Prefecture
proper noun
You've seen how 岐阜 is "Gifu." Now make it a prefecture to make Gifu prefecture.
ぎふけん
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
岐阜県に行くには、電車の乗り換えが必要ですか？
Do I have to change trains to get to Gifu prefecture?