U.S. President Dwight Eisenhower visited Bariloche as a guest of President Arturo Frondizi in 1960. Classical violinist Alberto Lysy established the string quartet, "Camerata Bariloche," here in 1967. During the 1950s, on the small island of Huemul, not far into lake Nahuel Huapi, former president Juan Domingo Perón tried to have the world's first fusion reactor built secretly. The project cost the equivalent of about $300 million modern US dollars, and it was never finished, due to the lack of the highly advanced technology that was needed. The Austrian Ronald Richter was in charge of the project. The facilities can still be visited, and are visible from certain locations on the coast. In 1995, Bariloche made headlines in the international press when it became known as a haven for Nazi war criminals, such as the former SS "Hauptsturmführer" Erich Priebke and SS officer Reinhard Kopps, known in Argentina as Juan Maler. Priebke had been the director of the German School of Bariloche for many years. In his 2004 book "Bariloche nazi-guía turística", Argentine author Abel Basti claims that Adolf Hitler and Eva Braun lived in the surroundings of Bariloche for many years after World War II. Basti said that the Argentine Nazis chose the estate of "Inalco" as Hitler's refuge. "Grey Wolf: The Escape of Adolf Hitler", a 2011 book (and subsequent film) by British authors Simon Dunstan and Gerrard Williams, proposed that Hitler and Eva Braun escaped from Berlin in 1945 and hid at Hacienda San Ramon, six miles east of Bariloche, until the early 1960s. These accounts are disputed by most historians, who generally believe that Hitler and Braun committed suicide in the last days of the Second World War. Tourism, both domestic and international, is the main economic activity of Bariloche throughout the year. The city is very popular with Brazilians, Europeans and Israelis. One of the most popular activities is skiing, and most tourists visit Bariloche in winter (June–September). Regular flights from Buenos Aires via LAN airlines and Aerolíneas Argentinas serve the city year round. The main ski slopes are the ones at Cerro Catedral, the biggest ski resort in South America and in the southern hemisphere. During the summer, beautiful beaches such as Playa Bonita and Villa Tacul welcome sun-bathers; brave lake swimmers venture into its cold waters (chilled by melting snow).