港

Three drops of water on the left - the contracted form of 水. The indexing radical here. Harbours, ports, and inlets are water bodies, so the radical is literal. Same radical heads 河, 湖, 海, 沟 - the river/water family that includes other water-channel words.

Right component supplies the sound (xiàng → gǎng, with significant Old Chinese drift between velar initials, but a regular pattern). 巷 itself means 'alley between walls' and adds a beautiful semantic echo: a harbour is a water-alley between landmasses, a narrow passage for boats. So 港 is etymologically 'an alleyway made of water'. The Hong Kong (香港 'fragrant harbour') reading uses this character.