ABSTRACT The Festival of Ancón, one of the first rock and roll festivals in Latin America, was held in a public park in the south of Medellín, between Friday, June 18 and Sunday, June 20, 1971. The goal of Ancón was to emulate Woodstock by holding a weekend-long event that would gather the best rock musicians in the country at an outdoor venue. Imitating Woodstock in Medellín, where rock was still in its infancy, was an extremely ambitious and bold idea. Overshadowed by several styles of Afro-Caribbean tropical music, as well as Argentinian tango, and Mexican ranchera songs, rock appealed to a small minority of mostly middle-class urban youth. Resources for its development were still limited, concerts were almost unheard of, and there were no rock promoters or concert organizers. In addition, Medellín, the second largest city in the country, with a population of about one million (in a country of 21 million), and the capital of the Department of Antioquia, was an unlikely site for such an event. An insular city, separated from the rest of the country by rugged territory, Medellín was considered as the most traditional and conservative urban center in Colombia, where the Catholic Church, protected by a constitution that gave it a religious monopoly, guarded private and public spheres. Forms of public entertainment were limited to and focused on sports or religious events, such as soccer games or Holy Week processions. In the following article, I am revisiting the Medellín of my youth to explore the planning of a rock festival in a city that was mistrustful and wary of it, the conflicting reactions to it, its significance in the history of rock in Colombia, and its repercussions.