KanjiJLPT N1
Cavern

Mnemonic

A hole in the rock wall seems to yield passage deeper underground. You squeeze through and gasp — an enormous cavern opens before you, vast enough to swallow a cathedral. The hole was merely the doorway; the cavern is the kingdom it yields.
Additional thoughts
Picture a tiny hole that yields open into a massive underground cavern — the contrast between the cramped entrance and the vast space beyond makes this memorable. Hole + Yield = Cavern.
Quick recall
A hole in the cliff yields passage into a breathtaking cavern beyond.

Details

The keyword for 窟 is cavern. This kanji refers to a large, deep cave or grotto, often one formed naturally in rock or earth. It carries connotations of a hollow, enclosed underground space, and by extension can refer to a den or lair where people or creatures gather in hiding. The character evokes imagery of dark, cavernous spaces carved into mountainsides or beneath the surface of the earth.
On'yomi
くつ、こつ
Kun'yomi
いわや、いはや、あな

Used in vocab