Vertical gardens
Fitting nature into densely-packed cities can be tricky, but green around us is not only good for our mental state but also our health: helping combat air pollution. Here we have a typically Japanese response to this problem: vertical gardens.
Using the walls of high-rise buildings to plant on gives all the benefits of having nature amongst us without the space that a huge grassy park would need. They also need less water when planted this way, so they have high eco-credentials, too.