The 9,820 sq km Yasuní National Park, a UNESCO Biosphere Reserve, lies downriver from Coca. It contains lowland rainforest of extraordinary richness — saltlicks where macaws and parrots gather in their hundreds, oxbow lakes patrolled by black caiman and giant otters, troops of red howler and squirrel monkeys, and a hundred and fifty species of frog.
Access is exclusively by boat down the Napo. Most visitors book a multi-day lodge stay (Sani, Napo Wildlife Center, Napo Cultural Center, Yasuní Kichwa Ecolodge) that includes guides, transport and food. Independent travel inside the park is restricted; the Waorani communities and the protected zones around them are off-limits. Permits and naturalist guides are arranged through the lodges in advance.