KanjiJLPT N2
Boulder

boulder, rock, cliff

Mnemonic

Atop the mountain, a colossal stone breaks free. This is no pebble — it's a boulder, massive and primordial, thundering downhill, carving a new ravine into the mountainside. The stone finally stops at the valley floor, half-buried, immovable for centuries.
Additional thoughts
The kanji stacks mountain (山) on top of stone (石). A stone so large it belongs to a mountain is, by definition, a boulder. Visualize the mountain birthing the stone.
Quick recall
A mountain births a giant stone — a thundering boulder.

Details

The keyword for 岩 is boulder. This kanji represents a large, imposing rock formation, typically one that is massive and firmly rooted in the landscape. It conveys the image of a great stone found on or near a mountain, suggesting ruggedness, permanence, and the raw power of nature. It is used to describe rocky cliffs, crags, and large natural stone formations.
On'yomi
がん
Kun'yomi
いわ