Genius idea or disaster in the making? Ever since Thomas Heatherwick got the green light to span the River Thames with a pedestrian bridge lined with trees, flowers and meandering walkways, the project has been accumulating naysayers. Called the “most expensive footbridge in the world”, it’s also received plenty of negative feedback for its location and potential policy for limiting the size of groups that can access it.

Whatever the outcome, the idea is intriguing. Lush visuals of the bridge promise a long, thin Eden arching over England’s iconic waterway. Practicalities aside–how do you keep aerial flower beds of that size green and healthy all year round?–this is a garden that redefines “green space”.