Giant Marble Run, Alice Holt FE.

Green Play Project served as both the designer and principal contractor for the giant marble run at Alice Holt Forest in partnership with Forestry England. The marble run forms part of a forest trail that invites children of all ages to explore and interact with the woodland environment through play. Consideration went into all aspects of the design; from the suitability and sustainability of the materials to the inclusivity and accessibility of all areas. This has ensured the experience is open, engaging and environmentally conscious.

There are six marble run locations within the site, each with its own character, themes and natural features, which informed the overall design and functionality of the marble run. This varied approach ensures that children (and adults) can explore, discover, and engage in different ways every time they visit, fostering a love of the outdoors. Branded wooden marbles are sold at the Visitor Centre, so everyone can follow the journey of their marble and keep it for their next visit.

Video courtesy of Alice Holt.

"Green play have done a lot of works on our site and we are always keen to have them included in future projects. Communication is always clear before, during and after works take place and the team are all friendly and approachable.”
Max Gravestock, Site Manager, Alice Holt Forestry England

Children playing on a treehouse in a wooded area during daytime.

Detail 01. The Owl

Alice Holt’s key feature is the new Owl marble run, this large sculptural play piece stands tall, looming through the trees adjacent to the dormouse play area. It’s a place children can interact at different levels, even peaking out through the owls eyes to watch the marble on its journey. This iconic piece reflects the history of play once found at Alice Holt, proving an exciting new play experience for children and a sense of nostalgia for adults who fondly remember the original owl.

A wooden ball rolling down a metal pipe on a makeshift ramp outdoors.

Detail 02. Sound

An unexpected element of the marble runs is the soundscape created as the balls travel through each structure. The roll of the ball across timber channels produces a gentle sound that echoes the calm of the forest itself. In some sections, chimes have been incorporated to create different sounds as the ball rolls down the trail. This natural harmony is part of what makes the experience so immersive. When a ball drops into one of the metal bowls, it creates a clear note that resonates through the trees, inviting a moment of pause, curiosity and sometimes even surprise. These moments of sound connect players not just to the installation, but to the surrounding environment in a multi-sensory interaction that goes beyond traditional play.

Two children, a girl and a boy, standing outdoors in a wooded area, observing a tall wooden climbing wall with a black sliding scale.

Detail 03. Bespoke Mechanisms

Many of our giant marble runs at Alice Holt have bespoke mechanisms that work within our designs to enhance and elevate the play. Our lifting mechanism (in areas 4 & 6) are clad in timber ensuring they blend into the natural landscape, they have been designed bespoke to move balls from ground level up to overhead channels. Children (both big and small) turn the wheel and watch their ball reach new heights, ready to start its journey along the channels.

A group of people gathered in a forest, standing on a dirt path, with a wooden structure that appears to be part of an outdoor exhibit or installation, surrounded by tall trees and sunlight filtering through the leaves.

Detail 04. Overhead Run

The channels at Alice Holt were designed specifically for the forest setting using two planks in a V shaped with a space in-between to allow rain water and any forest debris to pass through without blocking the path of the marble. This design also allows for the marbles to be viewed as they roll along overhead, encouraging users to look up into the forest canopy for a change in perspective.