I noticed special tiles running along the sidewalks while I was wandering around the cities of Sasebo and Fukuoka in Japan. My mom explained that they help blind people navigate the city. With my mind now aware of these tiles and their purpose, they became a secret code for me to try and decode. Straight-lined tiles indicated a path to follow; dotted tiles could be arranged to flag a split in the path or a waiting point (e.g. crosswalk or bus stop). At the Fukuoka airport, the trail leads you through the automatic doors to a split: the side-branch takes you to a map of the airport. The secret codes also had their secret hiding places: tiny balled-headed pins were embedded in a railing, nearly invisible to the naked eye, which they are not meant for, but easily detected by anyone using the railing for assistance up the stairs. I wonder what the message is, something informative, "Ten paces to next set of stairs," or something cloak-and-dagger, "Secret meeting when the thunder whispers, follow the trail."

In the US, I've seen similar sorts of tiles to guide you from a Mountain View bus stop to the Caltrain station, but there is less code and the implementation is incomplete. I was able to wander most of downtown Sasebo by following the trail at my feet, though there are gaps and it will not get you far into the residential areas. At Fukuoka airport they lead you to a map, but inside the airport there is no guide on the floor to lead you; perhaps the map provided an answer I could not read.