窟 is a Japanese kanji written with 13 strokes, listed here under the keyword “cavern”. It is built from 屈 (yield) and 穴 (hole). In Remembering the Kanji by James W. Heisig it is frame 1420.
On KumiJi Glyph Explorer, open the parts search and type “yield” + “hole”. 窟 is among the results, together with every other character containing the same shapes.
Open 窟 in the interactive kanji search
to expand every part down to its smallest pieces, add your own names and mnemonic stories,
or search for other characters by their parts.