What's Guardians of Metal and Concrete?
Welcome to Steel and Concrete Guardians (Tekkon)!
Tekkon is a game where players work together to photograph all of the world's infrastructure and show off their accomplishments. Tekkon players are called "Guardians." In Tekkon, players are called "guardians" because they protect social infrastructure. We are currently focusing on collecting data about manholes in Japan, and many guardians have submitted photos of manhole covers in the 23 districts of Tokyo. So go to the nearest manhole and take a photo! Even if you are not there, you can support local guardians by participating in the manhole photo evaluation! If you're not there, you can still support the local guardians by participating in the manhole photo review!
If you start this game today, you will be one of the Guardians, and you will work with other Guardians around the world to stop the infrastructure crisis!
Main game screen, map, and manhole


We started this project with the hope that citizens would not only consume social infrastructure services, but also be responsible for protecting them.
There are various types of infrastructure, such as roads and water supply. However, we focus on sewer manhole covers.
The aging of public infrastructures has become a serious issue, and the manholes are one of the infrastructures that are aging day by day. There might be cracked or damaged manholes around you.
It is up to every one of us to save these manholes and our society. By investigating and understanding the current condition of manholes, we can dramatically reduce the number of serious accidents in the future.

System Info

System Requirements
Web browser (Google Chrome highly recommended)
Supported OS
Android, iOS, Windows, acOS, Linux