沿岸
えんがん · engan · JLPT N1 · noun
seashore
沿 — water 氵 + 㕣 (marsh/valley) phonetic
沿 combines the water radical 氵 with 㕣, depicting a stream flowing through a small valley. Originally it meant to follow along the course of a river, and by extension came to mean 'to follow,' 'along,' or 'beside.' The 㕣 element also gives the sound.
岸 — mountain 山 on top + cliff 厂 + 干 (phonetic)
岸 is a semantic-phonetic compound. The top combines 山 (mountain) and 厂 (cliff/slope), suggesting a steep landform by the water; 干 underneath supplies the sound. Together it depicts a high bank or shore where land meets water.