There were once rumors of a mythological Ciudad Blanca, or "White City," laying hidden in the Central American jungle, overgrown with moss and trees. Then, to international intrigue, an aerial expedition found the settlement of legend in 2012 -- and later its ancient bowls, stone sculptures, and mostly buried ruins.

Though abandoned by people perhaps 1,000 years ago, biologists sought to find what now inhabited the ruined city, also known as "The Lost City of the Monkey God." A recent brazen expedition, requiring helicopters and protection by Honduran soldiers, discovered the White City teeming with wildlife. The deserted civilization is much more than an archaeological marvel.

"We wondered, the [Honduras] government wondered, and Hondurans wondered if there were other things special about this area," Trond Larsen, a Conservation International biologist who led the expedition, said in an interview.

"The answer is 'yes'," he added.

The ancient settlement is a rare instance of untrammeled wilderness, where jaguars, pumas, snakes, bats, frogs, birds, and insects thrive.

"There’s not many places left where we see a full community of species from the prey all the way up to the predators," said Larsen, who came face to face with a puma during the expedition.

What follows are some, out of hundreds, of the diverse species the 2017 expedition found. Overall, the observed creatures included 22 species never seen before in Honduras, two species thought to have been wiped out in Honduras, and a tiger beetle previously thought extinct.

"To discover that the Ciudad Blanca is teeming with flora and fauna is extremely promising as large expansions of undisturbed forest are becoming increasingly rare in Central America," said DaisyMaryon, a conservation biologist at Kanahau Utila Research and Conservation Facility in Honduras.

The rich diversity in Ciudad Blanca is positive, she noted, as 83 percent of wildlife populations in Latin America have declined since the 1970s -- mainly due to the destruction of habitat. The large mammals like jaguars and tapirs are certainly impressive, but the diversity of environmentally sensitive amphibians and reptiles are "particularly exciting," said Maryon, who took no part in the expedition.

"Their presence and diversity in the Ciudad Blanca indicate good health of the forest and ecosystem," she added.

The creatures

Worm salamander

Eyelash Viper

"A thriving population" of white-lipped peccaries

Fresh water crabs

Giant butterflies

Coral snake

Tapirs

The rare city

The lost city flourishes with life. It's secluded from modern human development, no roads travel anywhere close, and it's surrounded not just by mountain ridges but brush so thick explorers have to whack through the walls of vegetation.

But few lands on Earth are so fortunate. "Habitat loss is a struggle everywhere," noted Larson. "It's the main driver of species extinction."

"Climate change is exacerbating the problem," he added.

On a planet now dominated by humans, the solution -- if somewhat obvious but difficult to apply -- is to provide animals big swathes, or corridors, of land to thrive in.

"One 10 acre preserve is better than 10 one acre preserves," Robin Verble, an associate professor of biological sciences at Missouri University of Science and Technology, told Mashable last year.

"Pockets of forest can contain good numbers of diversity," said Maryon. "However these pockets need to be connected by a network of 'wildlife corridors' so terrestrial animals in particular can migrate and roam and to ensure good passage of genetic diversity throughout the region."

This means smart land use planning, explained Larson. It means accepting that grass-munching cows aren't going away, so choosing land for cattle that doesn't cut into a wildlife corridor. It means funding efforts to buy and protect vast swathes of land. And it means supporting policies and politicians that support meaningful land protection, like the recent establishment of over two million acres of forest in Peru's Yaguas National Park.

Finding thriving life in a long lost city wasn't an easy endeavor. But so it goes in the true wilderness, where chaos reigns and humans are outsiders.

"To me, if I’m in covered in mud, and insect bites, and infected with a parasite, I find that invigorating," said Larson. "It's part of the immersive experience of being in nature in its raw form."