The Laguna Grande is the centrepiece: a wide blackwater lagoon ringed by drowned forest, where you swim at dusk among pink river dolphins, watch the sunset from the boat and hear the forest change over. Dolphins surface here regularly and are the reserve's signature.

The narrow creeks and igapó off the main lagoon are the wildlife-rich water. Canoes drift under the canopy past squirrel monkeys crossing overhead, dusky titi and woolly monkeys, three-toed sloths, and the hoatzin colonies that crash about in the marginal branches.

The night boat is the reliable caiman activity — black and spectacled caiman picked out by torchlight along the banks, plus tree frogs, fishing bats and, occasionally, an anaconda.

The forest trails behind the lodges add the terrestrial layer: tarantulas, poison frogs, leafcutter columns and, with a good guide, tamandua and armadillo.

Water level shapes the visit as much as season. High water from roughly April to July floods the forest and makes canoe travel among the trees possible; low water from December to March exposes trails and beaches.

Practicalities

Access is via Lago Agrio, a short flight or long bus ride from Quito, then a road transfer to the bridge and two to three hours by motorised canoe. Lodges are simple and largely community-linked; the reserve is one of Ecuador's better-value Amazon options.

Cuyabeno sits in an oil-producing region, and the contrast between the reserve and the infrastructure around it is stark — part of what you are looking at, and worth reading about.