The "Devil's Gates" — an impressive narrow canyon closed at the top, deep in pristine cloudforest. Beyond it lies an otherworldly lagoon at the base of the 100-metre Paradise Fall, reachable only by climbing a three-metre cascade. The surrounding forest is home to the Cock of the Rock (the "Tunqui," symbol of the High Amazon) and the Quetzal.
The walk is demanding: you will wade through the river repeatedly and tackle some difficult climbs. But the crystal-clear water forms beautiful natural pools along the way, and you might find fossils of seashells in the riverbed rocks. Go with a guide.