Must the port be located on the national border?

Not necessarily. Ports refer to ports, airports, stations, cross-border passages and other specific areas that are open to the outside world with the approval of the central government or authorized provincial local governments and allow people, goods, articles and means of transport to enter and exit. In order to strengthen port management and show national sovereignty, the government often sends customs, border inspection and other law enforcement agencies to perform inspection, inspection, quarantine and supervision and management duties according to law. It can be seen that ports can be set up at both land borders and coastal ports, as well as airports and stations with entry and exit functions in mainland cities. In order to strengthen the management of all kinds of ports, China divides ports into two categories, namely, first-class ports and second-class ports. The first-class ports mainly refer to ports that allow China nationals and foreigners, goods, articles and means of transport to directly enter and leave the country by sea (river), land and air. Category II ports mainly refer to sea (river), land and air passenger and cargo ports that allow China nationals, goods, articles and means of transport to directly enter and exit, as well as railway stations, border rivers and ports and cross-border highway passages that allow people, goods, articles and means of transport from bilateral neighboring countries to directly enter and exit. According to different modes of transportation, ports are divided into water ports, dry ports and airports; According to the different opening hours of ports, they can be divided into all-weather ports and seasonal ports; According to the degree of port opening, it can be divided into completely open ports and restricted ports.