harbor
港 centers on a sheltered place where boats dock: a harbor or port.
港 combines 氵 (water) with 巷, which likely contributes the sound and the idea of a passage or lane, suggesting a water passage where boats can shelter.
Water 氵 beside 巷, which looks like a lane between buildings. Picture a water lane leading into a sheltered harbor.
For コウ, imagine a harbor with a big gate that says 'KO' (like 'company' abbreviated) — ships enter the KO harbor: KO -> コウ.
airport
harbour; harbor; port
Hong Kong
harbour; harbor
fishing harbour; fishing harbor
departure from a port; leaving port; setting sail
entry into port; arriving in harbor
port city; harbor city; harbour city
calling at a port
home port
opening a port (seaport, airport, etc.); starting operations at a port
Airport Line; Kūkō Line
Hong Kong dollar
returning to port
naval port; naval station
facing (along) the harbor (harbour)
harbor construction
inside the harbour; inside the harbor
hub airport
ice-free port