Upstream of the reservoir dam, the Odelouca River still runs freely through a narrow limestone canyon, forming natural swimming holes — rocky pools shaded by overhanging trees, cool and clean, used by local families in summer. The valley that was flooded downstream has a quiet, submerged quality; up here, the water is clear and cold and the canyon walls rise steeply on both sides. The pools near the village of Várzea are the most accessible.
Getting down to the river requires about 20 minutes on unmarked goat tracks from the nearest road. Go early or late in the day — the canyon traps heat and can become oppressive at midday in July and August. Bring sandals you can walk in and are happy to get wet, and expect no facilities of any kind. The reward is one of the best natural swimming spots in southern Portugal and almost no one at it.