Cuba
Tourist Visa Required? YES
Requirements

Attention: U.S. citizens need a U.S. Treasury Department license in order to engage in any transactions related to travel to and within Cuba (this includes the use of U.S. currency).  Before planning any travel to Cuba, U.S. citizens should contact the Licensing Division, Office of Foreign Assets Control, U.S. Department of Treasury, (202/622-2480) or on the Internet at www.treas.gov/ofac

Business Visa Required? YES
Requirements:

Attention: U.S. citizens need a U.S. Treasury Department license in order to engage in any transactions related to travel to and within Cuba (this includes the use of U.S. currency).  Before planning any travel to Cuba, U.S. citizens should contact the Licensing Division, Office of Foreign Assets Control, U.S. Department of Treasury, (202/622-2480) or on the Internet at www.treas.gov/ofac