Most nations in Europe do not require a U.S. passport holder to have a travel visa in order to gain entry. This includes all nations in the European Union as well as the U.K. and Scandinavia.
Not all nations welcome Americans with open arms. The Ukraine and the Baltic nations are among the few former Soviet states that do not require visas for travel or business. Georgia does not require a visa for tourists.
Japan, South Korea, Singapore, the Philippines, and Malaysia do not require visas. Thailand, French Polynesia, and many other South Pacific nations are open to tourists, though they may require a business visa.
South Africa, Morocco, Tunisia, Senegal, and the United Arab Emirates do not require visas, nor do tourists to Israel. United States passport holders wishing to travel elsewhere will need to have the proper documents (and the proper vaccinations).
Neither Canada nor Mexico require visas. Once Canada didn't even require a passport, but those days are gone. South America and the Caribbean are hit-and-miss, but many places like the Caymans, Ecuador and Argentina are open for tourists.
