Tres Chimbadas Lake in southeast Peru is about 30 miles from the border with Bolivia. It’s a small oxbow, a little over a mile long and less than 12 feet deep. The landscape of the lake is serene, but it’s mad with wildlife.

Jungle photography and catch-and-release piranha fishing are two big draws for Tres Chimbadas, and many people come for the giant river otters. They are the longest of all weasels, stretching over five feet from their whiskered faces to their flippy flat tails. Unlike other otters, they are a social bunch, and otter families come to the lake year after year to build their dens, and occasionally check out the eco-tourists.   

Despite the otters’ gruff and determined faces (trust—they’re cut when they’re pups), they are fairly subdued, if a bit territorial. Most important to keep in mind as a visitor, they are extremely endangered. Luckily lake guides take great care and caution when in their frisky presence, steering clear of babies and keeping noise down to a whisper.

The other main attraction is bird watching, and their names are just as apt to send you to Dr. Seuss as to your field guide. There’s the Wattled Jacana and Horned Screamer, a Rufescent Tiger Heron and White-cheeked Tody-tyrant, the sweetly shy Undulated Tinamou and the devoted Black-capped Donacobius. These little guys mate for life.