Yunnan snub-nosed monkeys are popular among people because of their humanlike faces with bright red lips. [Photo provided to China Daily]

Shangri-La is often envisioned as a paradise - for humans. It is, indeed, also an Eden for other primates, a monkey kingdom in the truest sense.

This is their domain, set aside for them to rule.

The monkeys are the animal species most easily viewed closest to the park's entrance because the area serves as their primary foraging grounds. Fortunate visitors watch them zip up and down trees on their mission to find food.

They're also fed by people like Yu Lizhong, one of 28 rangers from the neighboring villages who patrol the Shangri-La National Park of Yunnan Snub-nosed Monkeys.

"The monkeys feast on a 'banquet' breakfast around 9 am and then take long naps out of visitors' sight," Yu says.

Consequently, the park closes at noon.

Yu gets up at 5 am to start his patrols to track the monkeys and sometimes returns at 8 pm.

Only two of the monkey's daily meals are delivered, so they spend their waking hours scouring the landscape for leaves, bamboo and fruit. Visitors are forbidden from feeding them.

"We need to keep them wild," Yu says.

"After all, they're not in a zoo."