Location from EarthBound by Shigesato Itoi / Nintendo
A prehistoric cavern at the center of the Earth where dinosaurs roam and the party shrinks to the size of ants — the penultimate region before the end of the world.
The Lost Underworld is reached after completing Lumine Hall and is home to the eighth and final Your Sanctuary location, Fire Spring. The overworld sprites shrink dramatically, making the party look like specks against the dinosaur-scale landscape. Chomposaurs and Wetnosaurs are the primary threats. The outgoing Tenda here contrast sharply with their shy counterparts above. The Cave of the Past entrance is in the northwest. A talking rock explains the significance of the eight Sanctuaries. The Cloak of Kings, one of Poo's only equippable items, is found here. The ground shakes periodically as hot spring geysers erupt — blue ones restore HP/PP, red ones cure status effects. The Lost Underworld is where scale becomes the storytelling tool: you are very small, and the world is very old.
Massive underground landscape with dinosaurs towering overhead. The party sprites shrink to tiny size, emphasizing the scale. Lush prehistoric vegetation despite being underground. Hot spring geysers erupt periodically. A Tenda village exists here too — these Tenda are not shy.