A border checkpoint is a location on an international border where travelers or goods are inspected and allowed passage through. Authorization often is required to enter a country through its borders. Access-controlled borders often have a limited number of checkpoints where they can be crossed without legal sanctions. Arrangements or treaties may be formed to allow or mandate less restrained crossings. Land border checkpoints can be contrasted with the customs and immigration facilities at seaports, international airports, and other ports of entry.