Pacaya-Samiria National Reserve

The motorized canoe had been running for four hours before the lodges and tourist camps of the lower Marañón dropped out of sight behind us. My guide cut the engine, and the forest closed in — not dramatically, but the way a door closes gently behind you, and suddenly you are somewhere else. We were deep in the Pacaya-Samiria National Reserve, a protected area roughly the size of Switzerland, and the silence was full of things. Parrots arguing in a cecropia. The knock of a woodpecker so steady it sounded mechanical. A splash somewhere to the left that my guide identified, without looking, as a river otter.

Pacaya-Samiria is a flooded forest reserve, which means that for several months of the year the forest itself is underwater. I arrived in the shoulder season when the water was still high enough to take a dugout canoe through the trunks of trees that stood a meter deep in dark water, but the creatures were already beginning to concentrate. A giant river otter family — seven of them, screaming at us from the far bank — was my introduction to the reserve’s wildlife. They are enormous, loud, and completely without fear. Caimans floated in the margins like drift logs. A pair of pink river dolphins surfaced close enough that I could smell the fish on their breath, a detail no guidebook mentions.

The oxbow lakes inside the reserve — cochas, as the locals call them — are where the wildlife concentrates most densely. Victoria amazonica, the giant water lily, blooms here at night, its flowers opening white and closing pink by morning. On the evenings my guide paddled me out in the dark I would float among them while a single headlamp swept the black water catching the eyeshine of caimans along the bank. Thirty meters away, a black caiman held perfectly still in the reeds. My guide kept paddling at the same steady pace. I felt entirely safe and entirely awake in the way that good wilderness does to you.

The forest itself became familiar over five days in ways I hadn’t expected. I learned to recognize the sound of a failing tree before my guide told me what it was. I learned that the hoatzin — the prehistoric-looking bird with the orange crest and the deep, indignant groan — is never far from water and always positioned on the branch that will drop it into the river if you come too close. I learned that the smell of the flooded forest changes between morning and afternoon: cool and green at dawn, richer and more fermented by three in the afternoon when the heat had been on it for hours. These are the things you cannot read before you arrive.

When to go: June through October for concentrated wildlife and dry trail access. The high-water season from November to April opens canoe routes through the flooded forest that are inaccessible in the dry season, and the experience is spectacular in its own terms. Book a lodge deep in the reserve, not at the entry zone — the difference in wildlife density is not subtle and it costs nothing extra in effort to ask for this when booking.