expression, noun
last stand; last bastion; last stronghold; last frontier
Figurative expression for the final place or position of defense, resistance, or hope. Often used in military, political, or metaphorical contexts.
その古い城は反乱軍の最後の砦となった。
The old castle became the rebel army's last stronghold.
この小さな店は、地域の伝統工芸の最後の砦だ。
This small shop is the last bastion of the region's traditional crafts.
砦 alone means 'fort' or 'stronghold' in a literal sense. 最後の砦 is a set phrase with a figurative meaning of a final defensive position.
Compound of 最後 (last) + の (possessive particle) + 砦 (fort, stronghold). The phrase is a straightforward combination of its parts, used figuratively to mean a final defensive position.