The walkway is 18m above the ground (so not for the faint-hearted) and currently accessible only by a staircase. The original lift, intended to ferry wheelchair users and child buggies to the top, hasn't worked reliably since construction was completed and is now out of service until they come up with a replacement for it. Once at the top, you have a panoramic view of Kew Gardens and the city and countryside beyond. You are quite literally walking through the treetops and I'm sure that come late spring and summer, when the leaves have returned to the trees around, the experience will be different again when you'll be able to reach out and touch the foliage.
We also took a walk around the Temperate House, once the largest glass structure in the world and now the largest surviving Victorian glasshouse in the world. It's official, I now have greenhouse envy... My greenhouse will only fit 2 grow-bags on the floor plus a small staging unit for the pots of chillies - a bit on the tiny size compared to this one...