Headquarters of the United Nations
The C-1 visa is a transit visa issued to individuals who are traveling in "immediate and continuous transit through the United States en-route to another country". The only reason to enter the United States must be for transit purposes. A subtype C-2 visa is issued to diplomats transiting to and from the Headquarters of the United Nations and is limited to the vicinity of New York City. A subtype C-3 visa is issued to diplomats and their dependents transiting to and from their posted country.