Atlantis

Atlantis is a legendary island most notably utilized by the philosopher Plato. Though it's location is unknown (usually located either within the Mediterranean Sea or the Atlantic Ocean), it is notable for being an advanced civilization who were torn apart by war and destruction before sinking into oblivion.

Atlantis has been a notable location both within Super Sentai and Power Ranger series:
 * In Himitsu Sentai Gorenger, the team faced against a threat from the ancient city tied to Black Cross Army soldier Gear Mask.
 * In Dai Sentai Goggle V, leader Ken'ichi Akama (Goggle Red) received his powers tied to Atlantis, symbolized by the ruby gem he possessed.
 * In GoGo Sentai Boukenger, the Boukenger searched for the existence of Atlantis for their mentor Morio Makino. Though they found what appeared to be an Orihalcon container from Atlantis in Task 8: The Treasure of Atlantis, it turned out to be the container of the Vril, a shape-shifting monster that rampaged through SGS before finally being stopped.
 * In Boukenger's PR equivalent, Power Rangers Operation Overdrive, the team likewise searched and fought against threats from Atlantis.