pen, corral, cell, jail
檻 centers on a confined enclosure for holding living things: a pen or corral for animals, or a jail cell for people.
檻 combines 木 (wood) with 監, which likely contributes the sound and the idea of overseeing or enclosing. The character suggests a wooden enclosure for containment.
The left side is wood 木, and the right side 監 looks like a watchful eye over a container. Picture a wooden pen where animals are kept under watch.
For カン, imagine a can made of wood that serves as a tiny jail: can -> カン, and the wooden can holds the prisoner.