要よう害がい

noun

stronghold; fortress

Refers to a fortified place or natural defensive position, often in historical or military contexts.

• その城しろは天てん然ねんの要よう害がいに建たてられた。

  The castle was built on a natural stronghold.

noun, noun which may take the genitive case particle 'no'

strategic position; key position

Used for a location or point that is strategically important, not necessarily fortified. Can also be used attributively with の.

• この港みなとは貿ぼう易えきの要よう害がいの地ちだ。

  This port is a strategic location for trade.