The silent unknown abyssTorrents of suspicionTruth that pierces cloudsThe proud, tall waves —Floor descriptions, Undersea Grotto Undersea Grotto is the second stratum in Etrian Odyssey III: The Drowned City. This strange maze appears as though it is located under the ocean, yet seemingly allows breathable air for explorers to venture. Many species of starfish, walruses, and coral inhabit this place.