The Cañón del Atuel is the reason most visitors come to San Rafael who are not coming for wine. The Atuel River has carved through layers of red, orange, and ochre sandstone to create a canyon of real drama — 50 kilometres of cliffs, hoodoos, and improbable rock formations, stretched between the Valle Grande reservoir at the upper end and the smaller Los Reyunos at the lower.
The standard route is the day-loop drive from San Rafael, about 200 kilometres round-trip via Valle Grande and back. The road descends from the high reservoir into the canyon proper, threading past viewpoints with names like the Cathedral and the Submarine. Rafting trips run from Valle Grande down through the upper rapids — grades II to III, suitable for first-timers. Below, the river quietens and the canyon broadens into the Cañón del Atuel proper.
Allow a full day. Stops include the hydroelectric dams, the strange erosion formations, and the Christ of Aguada beach if you swim.