The term 'Big Three Site' refers to the Yalta Conference, which was a meeting of the Allied leaders of World War II in February 1945. The conference was attended by the 'Big Three' Allied leaders: U.S. President Franklin D. Roosevelt, British Prime Minister Winston Churchill, and Soviet Premier Joseph Stalin. The conference was held in Yalta, a resort town on the Crimean Peninsula in the Soviet Union. The purpose of the conference was to discuss the post-war reorganization of Europe and Asia.