Good Question: Why aren’t manholes flush with the street? 02:36 MINNEAPOLIS-- Drivers hit bumps in the road almost every time they drive.Sometimes it's a pothole. Others it's a manhole cover ...

Artistic manhole covers 03:39. On the streets of Japan, if you spend too much time staring at your phone, you might just miss what's right under your feet.

It takes viewers behind the scenes of the largest manhole cover manufacturer in the country, Hinode Suido, in operation for more than 100 years. Subscribe to the Design newsletter.