Only in Japan is it possible to ride a crowded train to work, stop to buy your "o-bento" lunch at the convenience store, and arrive at work -- all without ever having eye contact with anyone. That is because people spend a lot of time looking at the ground in Japan.
This must be why Japanese pay so much attention to things on the ground. Manhole covers are often decorated, and I am pretty sure there are professional "sidewalk designers" who conjure up the detailed tiled patterns of sidewalks, which often include one meticulously painted brick every hundred meters. If you had your artwork appear on a manhole cover in Japan, your work would be seen by more people than the Mona Lisa. And people would be just as happy to not have to go all the way to a special wall in France to see it.
With all those people looking at the ground on their way to work, I have often thought they should line the sidewalks with newspaper. With the Japanese vertical writing system, we could at least read the news on the way to work.