San Carlos de Bariloche (from the Mapuche name Vuriloche, meaning "people from the other side of the mountain"), commonly known simply as Bariloche (Spanish pronunciation: [baɾiˈlotʃe]), is the largest city in the Argentine province of Río Negro and the seat of the department of the same name. It is located in the foothills of the Patagonian Andes on the southern shore of Nahuel Huapi Lake, near the border with Chile. With a population of 135,755 according to the 2022 census, Bariloche is a mid-sized city by national standards but holds significant regional importance, being not only the most populous city in its province but also the largest in the Patagonian Andes, and the third largest in the entire Argentine Patagonia following Neuquén and Comodoro Rivadavia. Its urban zone is characterized by its low density and has an area of more than 220 square kilometres (85 sq mi), extending longitudinally from east to west for about 50 kilometres (31 mi).

Bariloche's economy is heavily centered on tourism, making it the country's third most visited destination after Buenos Aires and Mar del Plata, as well as the most popular destination in all of Patagonia. It attracts visitors year-round for its scenic natural setting including Nahuel Huapi National Park and other reserves, offering a range of activities such as skiing in winter and water sports and hiking in summer, alongside diverse accommodations and dining options. The nearby Cerro Catedral is the largest ski resort in South America. The city is a traditional hub for student tourism in Argentina, hosting the customary high school graduation trips, as well as 15th birthday celebrations from neighboring countries. In 2012, a law passed by the Argentine Congress declared Bariloche the "National Capital of Adventure Tourism". In addition to tourism, scientific activities are also of growing importance for the city, as it hosts the National Atomic Energy Commission's Bariloche Atomic Centre, as well as the public universities of Comahue, Río Negro and the National Technological.

The name Bariloche comes from the Mapudungun word Vuriloche meaning "people from behind the mountain" (vuri = behind, che = people). The Poya people used the Vuriloche pass to cross the Andes, keeping it secret from the Spanish priests for a long time.^{[citation needed]}

There is evidence of the existence of indigenous settlements on banks of Lake Nahuel Huapi, in the area now occupied by the city of Bariloche, prior to arrival of expeditionaries and white settlers. During the Neolithic, the arrival of human beings to Nahuel Huapi region occurs. The archaeological and historical record speaks of tehuelches and puelches presence in the area. With the process of araucanization and mainly since the 17th century, the culture of these groups is strongly affected by Mapuches, who increased their presence from the settlement of Spaniards in Chile, and their continued push east.

At 19th century end, in the vicinity of Nahuel Huapi, only a few scattered indigenous families were there: People of Inacayal had been stripped of their lands, and transferred to Tecka (Chubut) when the cacique was taken prisoner.^{[citation needed]} Curruhinca had made an act of submission to Argentine government with his own. Some Nguillatun was still being celebrated.^{[citation needed]}

But the region was beginning a new stage in its history. Although incorporated into national sovereignty, the Nahuel Huapi area began to develop fundamentally linked to Chile. Before 19th century end, when the border was still in dispute, people from the south of the neighboring country were gradually arriving to settle in surroundings of the lake. Small farmers were most of them from the island of Chiloe, but German immigrants living in Chile also arrived.

Nahuel Huapi lake was known to Spaniards since the times of the Conquest of Chile. Following the trails of the Mapuche people across the Andes, in the summer of 1552–1553, the Spanish Governor of the Captaincy of Chile Pedro de Valdivia sent Francisco de Villagra to explore the area east of the Andes at the latitudes of the city of Valdivia. Francisco de Villagra crossed the Andes through Mamuil Malal Pass and headed south until reaching Limay River in the vicinity of Nahuel Huapi Lake.

Another early Spaniard to visit the zone of Nahuel Huapi Lake was the Jesuit priest Diego de Rosales. He had been ordered to the area by the Governor of Chile Antonio de Acuña Cabrera, who was concerned about the unrest of the native Puelche and Poya after the slave-hunting expeditions carried out by Luis Ponce de León in 1649, who captured Indians and sold them into slavery. Diego de Rosales started his journey at the ruins of Villarica in Chile, crossed the Andes through Mamuil Malal Pass, and traveled further south along the eastern Andean valleys, reaching Nahuel Huapi Lake in 1650.