One of the many advantages to locating in Illinois is the availability of foreign trade zones and subzones to companies wishing to ship products or component parts into the United States. A foreign trade zone (FTZ) is a site within the U.S.A. where foreign and domestic merchandise is considered to be outside of U.S. Customs territory. Foreign or domestic merchandise may enter this enclave without formal Customs entry or the payment of Customs duties or excise taxes. The FTZs are enclosed and policed areas, operated as a public utility, in or adjacent to a U.S. Customs Port of Entry, with facilities for loading, handling, storing, manipulating, manufacturing and exhibiting goods. FTZs are under the supervision of U.S. Customs, but the zones are considered outside Customs territory. Typically, a FTZ includes a warehouse and open land area for industrial or warehouse development, on a site or sites in close proximity. The purpose of establishing a FTZ is to attract economic activity consistent with national policy. Ideally, this activity would include attracting foreign investment to the U.S. and encouraging domestic firms to expand their international trade activity. Tenants of FTZs vary from small import export companies to large multi-national manufacturing companies.