Volcanoes National Park in northern Rwanda is renowned among animal enthusiasts as one of the last places on earth to see the critically endangered mountain gorilla. These enormous animals — adult males can approach 500 pounds — live on the forested slopes of the Virunga Mountains, and guided visits are among the premier tourist activities in East Africa. But popular as these excursions might be, Volcanoes National Park is home to more than just one rare and charismatic primate.

The golden monkey, named for the rich golden patch that runs the length of its back, also thrives in the park’s densely wooded slopes. Other than sharing a taste for young bamboo shoots, these monkeys are distinct from the mountain gorillas in almost every way. They spend most of their lives in the trees, and while the gorilla families are generally presided over by a single breeding male — a silverback — it is the female golden monkeys who lead their group, banding together to fight off predators such as eagles and feral dogs.

While their exact numbers and distribution are unknown, this unique species of monkey is almost entirely restricted to the Virunga Mountains and has been listed as endangered by the International Union for Conservation of Nature since 1996.

Volcanoes National Park is one of the only places in the world where tourists can track the golden monkey and spend an hour with one of their active and playful family groups. The monkeys have been habituated, so they do not hesitate to approach as they go about their morning routine — offering a remarkably intimate encounter for visitors.

If they lived anywhere else, the golden monkeys might be better known. But as neighbor to one of the animal world’s superstars, they can be easy to miss.

“They’re like the little brother,” said Faustin Twizerimana, a hotel manager who works just steps from the park. Twizerimana grew up in the area and remembers being captivated by the golden monkeys when he was younger, watching them jump from tree to tree.

While the overwhelming majority of park visitors come to see the mountain gorillas, this may slowly be changing. Twizerimana estimates that in his establishment, as many as 35 percent of the guests now come expressly to see the golden monkeys. When asked why the tourists come, he answers simply: “The monkeys are wonderful.”

One possible reason for the slight upswing in visitors is a growing awareness of how accessible the golden monkeys are and how comparably affordable the experience is.

Volcanoes National Park is a little more than two hours from Kigali on a well-maintained tarmac road, making it a feasible day trip for early risers or a leisurely overnight. While there is no place to stay in the park itself, the nearby towns of Musanze and Kinigi offer a range of accommodation options — everything from clean, basic dormitory-style bunks to posh eco-lodges that run upward of US$600 a night.

The fee to visit the golden monkeys (which includes the services of a guide and several expert trackers) is just a fraction of that to see the mountain gorillas, and the hike itself is much less strenuous. Visitors can expect a relatively gentle climb through the farmland surrounding the park, followed by a beautiful if muddy walk into the bamboo forest.

Mary Wozniak, an American tourist visiting Rwanda from her home in Peru, recently added a day to her gorilla trek to see the golden monkeys. About both experiences, she notes: “You get to see up close that your money goes toward protecting the next generation.”

Together with their “big brothers,” the golden monkeys are bringing essential revenue to Volcanoes National Park, contributing not only to their own preservation but also to the preservation of their entire ecosystem. Just as the park would not be complete without these unique and beautiful creatures, nor is any trip to Rwanda complete without a visit to experience them.