noun
landlocked prefecture
Refers to a prefecture with no coastline. Often used in discussions of geography, tourism, or regional characteristics.
日本には海なし県が8つあります。
There are eight landlocked prefectures in Japan.
海なし県の住民は、夏になると海のある県へ旅行することが多い。
Residents of landlocked prefectures often travel to coastal prefectures in the summer.
内陸県 also means 'inland prefecture' but emphasizes being far from the sea rather than simply lacking a coastline. 海なし県 is more colloquial and directly highlights the absence of a sea border.
Compound of 海 (umi, 'sea') + なし (nashi, 'without') + 県 (ken, 'prefecture'). The spelling 海なし県 is the most common modern form.