"가닿다" and "닿다"
닿다 is a common word with many meanings, but they all seem to originate from "touch" and "reach".
* 손이 물에 닿았다 (touch) / 손이 닿지(를) 않는다 (touch, reach) / 배가 육지에 닿았다 (reach)
가닿다 is not as widely used, actually very seldom in daily life. It is more literary.
가닿다 is 가다(go) + 닿다 -> 가 닿다 -> 가닿다, and means something moves towards and finally ends up at a place.
It is often used figuratively, as with a personal interest, a glance or gaze, etc.
- 배는 이국의 항구에 가닿았다 [닿았다]: The ship came to a harbor in a foreign land.
- 그의 시선이 그녀의 얼굴에 가닿는다: His eyes find their way to her face.
- 그녀의 정성이 그의 마음에 가닿았다: Her devotion has reached and touched his heart.