Kirstenbosch National Botanical Garden

This guide to Kirstenbosch National Botanical Garden in Cape Town follows architect Mark Thomas, who set out to mark the garden's hundredth birthday with a canopy walkway and sketched not a bridge but a boomslang, the tree-dwelling snake that gives the structure its name. It traces how engineer Henry Fagan and project architect Chris Bisset built its steel spine, prefabricated off site in six-metre sections and lowered into the Enchanted Forest without felling a single tree. Feel the spine flex faintly underfoot as you walk its curve.