The mountain gorillas looked me over with what I took to be boredom, but the rangers leading me knew better.
When a male gorilla let out a low, two-note murmur, the rangers responded by making the same sound, as if to say: "We've come as friends."
A young ape sat high in a tree overhead, yanking down a feast of leaves, while a second was splayed out in the tall grass, slapping his head and kicking his legs playfully. But it was clear the male, an enormous animal with glistening white teeth, was keeping an eye on things.
Virunga National Park, a World Heritage site in the restive eastern region of the Democratic Republic of Congo (DRC), just might be the world's most spectacular, under-visited park.
Stretching 185 miles (300 km) north to south and encompassing 2 million acres (81,000 hectares) of lush forest and savannah, it is Africa's oldest national park, established in 1925 when Congo was still a Belgian colony.
It is also the only park in the world with three kinds of great ape - mountain gorillas, chimpanzees and lowland gorillas - and is home to many of the world's mountain gorillas, which are thought to number fewer than 800.
But Virunga, the setting for American conservationist Dian Fossey's 1984 book "Gorillas in the Mist," is difficult to get to and the security situation is perennially uncertain.
Two decades of conflict violence, hunger and disease have claimed the lives of millions of people in this central African country, once known as Zaire.
The park was closed throughout last year, as rebel groups, including the M23, used it for cover during an uprising. Virunga reopened to visitors last January.
Just days after my visit in April, Virunga's chief warden, Emmanuel de Merode, a Belgian prince, was ambushed and seriously wounded.
"The vast majority of visitors wouldn't come to Virunga because of their perceptions of safety," de Merode told me days before that incident. "But we're not ready to take on vast numbers of visitors, so we gladly accept those who are prepared for, or even welcome, a level of risk."
EMERGING FROM FOG OF WAR
Virunga is a day trip from Goma, which sits on the banks of Lake Kivu in the shadow of the Nyiragongo Volcano, and has a number of hotels and restaurants. Visitors can also stay in the park at Mikeno Lodge, which is right in the forest. A gorilla trekking permit costs $465 per day.