城砦

じょうさい【城砦】

a fortress; a stronghold; a citadel.

●難攻不落の[堅固な]城砦 an impregnable [a secure] fortress.

●城砦を築く construct [build] a fortress

・城砦を攻める attack a fortress.

●城砦は険しい山の上にあった. The fortress was perched upon a mountain with a difficult approach.

城塞都市 a fortified city.