Hong Kong's new breed of kindergartens: no classroom, no uniform, just kids outside playing and having fun in the dirt

On a recent Sunday in Tai Po Kau Nature Reserve, teacher Danie Strydom and a few preschoolers were using the slippery face of a river boulder as a slide. Just a few metres away, another group of children were carefully building, branch by branch, pebble by pebble, a riverbank shelter for "forest elves".

Welcome to Hong Kong Forest Kindergarten. It's among several nature-based nurseries that have emerged in the city, operating without classrooms or uniforms. While most kindergartens in Hong Kong adopt an academic approach, a few educators are advocating the power of outdoor play, exploration and nature during this critical period in a child's development.

Strydom had started his open-air classes in March as an eight-week experiment, inspired by the Swiss documentary . But two months turned into eight months, a handful of toddlers became hundreds, and the one-man band grew into a team of four. Now his playschool explores countryside destinations from Tai Tong Eco Park in Yuen Long to Lions Nature Education Centre in Sai Kung.

"The children take to it like fish to water when they enter the forest. I am astonished every day at how creative they are and how comfortable they are in nature. I call it the magic of play," says Strydom, a long-time volunteer for youth development projects worldwide.

He was always out and about when growing up in South Africa; he enjoyed camping overnight at his family farm in the Northern Cape and grilling fish he caught with self-made spears over a fire.

"I wanted to be like Huckleberry Finn and Tom Sawyer," says Strydom, who attributes his confidence and fortitude to those childhood adventures. "Whatever life throws at me, I know I will be OK because I have those experiences on the farm."