I was recently walking down a road when a car came my way (I'm an inveterate jaywalker). I moved over to the sidewalk, only to notice it clearly wasn't a sidewalk at all. The pavement looked like this:
The paving stones are embedded into and perpendicular to the ground, making it rather uncomfortable to walk on!
Now, what is the purpose of such pavement? Is this layout meant to improve drainage in case of rain (this is in London, so it's always raining)? But then why pave the ground at all instead of simply using grass or greenery to anchor the soil and prevent erosion?