There a total of 18 Supertrees in Gardens by the Bay, all covered with over 160,000 varieties of plants. Twelve of the Supertrees can be found here in the Supertree Grove. The tallest one stands at 50m.
What you see above is the aerial walkway connecting the Supertrees together. Suspended by cables, it has a grille path that allows you to look straight down.
Be warned, that smart-phone you are carrying will fit nicely through the grilles so please don't drop them while you're up there !