The Sendero Macuco is a seven-kilometre return hike that leaves the road back from Cataratas Station and dives into the forest. It is the only walk in the park where you are likely to be alone, and the only one where you have any real chance of seeing wildlife — agoutis, capuchin and howler monkeys, toucans, and (very rarely) the elusive ocelot.
The trail ends at Salto Arrechea, a single 20-metre waterfall in a fern-fringed plunge pool. Swimming is allowed and the water is wonderfully cold after the walk. Allow three hours and start before 10 am if you want to beat the worst of the heat. Bring water and insect repellent.