KanjiJLPT N4
Place

place, extent

Mnemonic

You find a door with an axe buried deep in it. Someone has marked this place — driven their axe into the door as a claim: "This is MY place!" Every door around here bears an axe scar, each one declaring ownership of the place behind it.
Additional thoughts
Picture a frontier settler slamming an axe into a cabin door to stake their claim. The axe lodged in the door is the universal sign: this place is taken. Door on the left, axe on the right, together they form the kanji.
Quick recall
An axe slammed into a door stakes a claim on this place.

Details

The keyword for 所 is place. This kanji refers to a location, spot, or position where something exists or where an activity takes place. It is one of the most commonly used kanji for indicating a general area or setting, and it frequently appears in compound words related to specific types of locations or institutions. It can also function grammatically to nominalize verbs, turning actions into "the place where" or "the thing that" something occurs.
On'yomi
しょ
Kun'yomi
ところ、-ところ、どころ、とこ