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). Lake Nahuel Huapi averages 14 °C (57 °F) in the summertime. Bariloche is the biggest city of a huge Lakes District, and it serves as a base for many excursions in the region. Activities such as fishing, whitewater rafting, and birdwatching are popular with tourists. Trekking along trails in the nearby mountain wilderness is supported by a few high-mountain huts operated by the Club Andino Bariloche. The city is noted for its chocolates and Swiss-style architecture. Many high school students in Argentina take a senior trip to Bariloche, and the town is well prepared to host these kinds of groups. In November 2012, Bariloche was named „national capital of adventure tourism“ under Law 26802 sanctioned by the Argentine National Congress.