In some areas of Japan, they cover their manholes with beautifully designed one-of-a-kind covers.
This isn't limited to one or two pieces, either.
The Asian trend is covered on a number of web sites. In fact, a search on Google images will result in all the manhole covers you can handle.
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Implications - The development of decorative pieces to be used in the streets during daily life is a way for certain areas to add a more attractive, upbeat element to their citizens' daily lives. This is seen everywhere from the painting of houses in Rio de Janeiro to covering manholes with art in Japan.