Cities are built for efficiency, but that can also make them monotonous. The human body was not designed to walk endlessly on flat surfaces. By creating more physically challenging urban environments people can get more of the exercise they need, but also reconnect with a sense of playfulness than many adults secretly yearn for in everyday life, writes Anna Boldina.

Homo sapience developed thousands of years ago, in wild grassy lands full of physical challenges and this is what our bodies are optimized for through evolution. Throughout more recent human history, city dwellers have walked on a whole variety of surfaces: cobbled stones, steppingstones, gravel; balancing on narrow boards over ditches, stepped over holes and up the level changes. Navigating this environment is still part of everyday life in less economically developed countries. The remains of a less regulated environment can be seen in historic towns, such as Cambridge or Coimbra. Gradually, most of those landscapes are being replaced with tarmac to facilitate vehicle movement and make places more accessible, as well as for eliminating the chance of injuries and insurance claims.