These are delightful.
After World War II, city planners in Japan proposed the idea of allowing each local municipality to design their own manhole cover as part of an effort to raise awareness for costly sewage projects. Designs would reflect local industry, culture, and history. The result was a huge success, and now over 19,000 manhole cover designs can be found embedded across 95% of all municipalities in Japan.
This video takes you on a tour of the factory where the community-driven designs are manufactured:
(via Colossal)