The Office of Global Engagement offers guidance in passport and visa acquisition, though these important travel documents are ultimately the responsibility of the traveling student. In many cases, you will be required to travel to the U.S. regional consulate (usually in Washington, D.C.) of the country in which you wish to study. Each country has unique student visa application requirements, and for some countries a visa is not required for summer programs.
U.S. students studying in he UK for less than 6 months may enter as a 'student visitor' and do not need a Tier 4 Student Visa. However, you must present your letter of acceptance into a study abroad or exchange program to the UK Border Agency upon entry.
The official British Government website for online visa applications
U.S. students studying in France for less than 90 days may enter without a visa.
U.S. students studying in Spain for less than 90 days may enter without a visa.