Nauyaca Falls is a powerful two-tier waterfall southwest of San Isidro, reached by road and trail in the direction of Dominical. The lower pool is the prize: wide, cold, and dramatic enough to justify the detour.
Go early, wear proper footwear, and check current access arrangements before setting out. Rain can make the trail muddy and the water forceful, which is part of the appeal but also the reason to avoid treating it casually.