Los Reyunos is the lower of the two reservoirs on the Atuel — a long, narrow lake squeezed between sandstone cliffs about 35 kilometres west of San Rafael. It is smaller and quieter than Valle Grande and most local trippers come here for the swimming, fishing, and waterskiing rather than the scenery.
A few hosterías and campsites sit along the lake. The pumped-storage hydroelectric plant at the dam is one of the few of its kind in South America, and tours are sometimes available. The drive in passes through low, dramatic rock terrain — worth doing even if you don't stop.