Pain isn’t always a bad thing. Really. Right now, for example, you’re grimacing and trying not to contort your body as a masseuse works on the charley horse in your calf. But it’s not easy. After a full day of hiking—and climbing and scooching and paddling—your muscles are tense. The thought of heading back out tomorrow makes you cringe. If you can just work through the pain and pay attention to the gorgeous view, though, the rest of your trip won’t be ruined.

You’re in Yasuni National Park, one of the most biodiverse areas on the entire planet. That’s not surprising, since the park is part of the Amazon. Its Napo moist forests contribute to the rainforest. More species of fish live here than in the vast Mississippi River Basin. One-third of the Amazon’s bird species—more than Canada and the United States combined—are found here. One-third of the world’s amphibians and reptiles are in the area. While some indigenous tribes have yet to receive contact from the outside world. This is not an experience you want to sit out.

Yasuni National Park was established in 1979 and later named a biosphere reserve, as well. It covers nearly 4,000 square miles in eastern Ecuador. Aside from the rainforest, it’s home to hidden waterfalls, peaceful lakes, slow-moving rivers, slippery hiking trails, and stunning lookout points. It’s also where you find La Selva Amazon Ecolodge & Spa.

La Selva Amazon Ecolodge sits on the edge of remote Lake Garzacocha. There are no roads around here. To reach the lodge, you boarded a locally crafted canoe in Coca and floated up the Napo River, which eventually flows into the mighty Amazon. As you slowly moved through the jungle, you listened for woodpeckers, scanned the trees for monkeys, kept one eye on the water for caimans, and peeled off layers as the humidity increased. It didn’t feel like two hours had passed when you reached the lodge.

The lodge, by the way, is exactly what you’d hope for when you planned this trip years ago in your mind. Wooden docks—with sun loungers and umbrellas atop them—extend over the lake. Tied-up kayaks sway in the calm water. The docks lead uphill to the main lodge, which is made of bamboo. Airy cabanas, featuring fine nets instead of glass windows, are behind it. While you’re never far from the sound of rustling leaves and calling birds.

So you couldn’t stay inside, of course. You started following the Strangler Trail to find its namesake figs that grow around and choke trees, the Marmoset Trail to search out rare pygmy marmosets (the smallest monkeys in the world), and the Sacha Hugra Trail to see the only surviving original primary forest. You also climbed the Rainforest Canopy Observation Tower for a 360-view of the rainforest and walked to the clay lick to see hundreds of brightly colored parrots. No wonder you need a legs and calves massage right now.