In general, a
port of entry (POE) is a place where one may lawfully enter a country. It typically has a staff of people who check
passports and
visas and inspect luggage to assure that
contraband is not imported.
International airports are usually ports of entry, as are road and rail crossings on a land
border.
Seaports can be used as ports of entry only if a dedicated
customs presence is posted there. The choice of whether to become a port of entry is up to the civil authority controlling the port.