KanjiJLPT N2
Core

heart, interior

Mnemonic

A single drop of water seeps through a tunnel, falling past ancient rice paddies hidden in total darkness. A big cavern opens at the very end—the sacred core no outsider has ever reached.
Additional thoughts
Picture crawling deeper and deeper through a narrow tunnel, water dripping on your neck, passing eerie underground rice fields, until you emerge into a vast hidden cavern—the unreachable core of the earth itself.
Quick recall
A drop through a tunnel, past hidden rice, into a big cavern—the core.

Details

The keyword for 奥 is core. This kanji conveys the idea of something deep within, the innermost part of a space or concept that is not easily reached or seen. It suggests the hidden interior or depths of a room, building, or even an abstract matter—the part furthest from the entrance or surface. By extension, it carries connotations of profundity, mystery, and the essential heart of something.
On'yomi
おう
Kun'yomi
おく、おく.まる、くま