4 links have been added on this idea.
  1. Good application for this would be between skyscrapers, just for the effect, I mean, look at this proposal. https://www.dezeen.com/2015/09/28/diamond-lotus-vo-trong-nghia-trio-housing-towers-bamboo-plants-bridges-ho-chi-minh-city-vietnam/

  2. So they exist already, how come there aren’t loads of them. I guess they are cheaper than heaps of humpback footbridges over canals.