Architects Marks Barfield Architects designed the Xstrata bridge, leading from the top of one tree to another, as well as the underground tunnel Rhizotron (from the Greek “riza” - root), through which you can get acquainted with the root system of plants growing in the botanical garden.
The opening of these two buildings coincides with the start of the Kew Tree Festival, scheduled for late May.
Visitors will be able to walk along the bridge, located at a height of 18 m and a length of 200 m, and examine in detail the structure of tree crowns: in fact, it is an open-air classroom. The Xstrata has a capacity of 3,000 people per day. Its frame is made of self-passivating steel, which will darken over time and blend in with the tones of the foliage and bark of the surrounding trees. The pillars of the bridge are reinforced in concrete pits 12 - 18 m deep, positioned so as not to damage the roots of the trees. The "balusters" of the Xstrata handrail are arranged according to the Fibonacci number sequence, which also describes natural structures such as the arrangement of scales in pine cones or petals in buds.
The Rhizotron Tunnel is the only underground "exhibition" in the British Isles dedicated to the root systems of trees, their structure and features. It is made of concrete, and the entrance to it is designed as a ramp leading into the ground. Inside, a system of bronze pipes is fortified on its walls, in which you can see interactive installations, and stained glass windows with LED lighting tell about the symbiosis of mushrooms and tree roots.