幽深 (yōu shēn) is an adjective describing a place that is both deeply recessed and quietly secluded—often evoking mystery, tranquility, or quiet grandeur. The first character 幽 (yōu) means 'secluded', 'quiet', or 'dim', suggesting remoteness and hushed atmosphere; the second character 深 (shēn) means 'deep', referring to physical depth (e.g., a valley or forest), spatial remoteness, or even metaphorical depth (e.g., profound stillness). Together, they form a literary, slightly poetic compound emphasizing layered seclusion: not just far away, but hidden, shaded, and hushed.

This word is commonly used to describe natural landscapes—dense bamboo groves, mist-covered mountain gorges, ancient temple courtyards, or narrow alleyways in old towns. It appears frequently in descriptive writing, travel essays, and classical poetry, but rarely in casual speech. Because it carries an aesthetic and contemplative tone, 幽深 often implies beauty born of quiet isolation, not emptiness or danger.