The Japanese government has released a Minecraft map of the world's largest underground floodwater diversion system. This free download allows you to explore one of the Tokyo area's unique landmarks from your own home.
The facility, officially named the Metropolitan Area Outer Underground Discharge Channel and commonly called G-Cans, acts as a real-world disaster prevention system. It is famous for its "pressure adjustment tank" – a vast underground chamber supported by 59 massive pillars. This breathtaking, almost cinematic space is the most recognizable part of G-Cans and is often referred to as the "underground temple" in Japan. Its dramatic atmosphere has made it a popular filming location for music videos, Japanese TV dramas such as Kamen Rider, and movies.
While public tours of G-Cans are available during dry periods, the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) now offers a virtual tour within Minecraft. The ministry has published a video on its official YouTube channel explaining the purpose of G-Cans and showcasing its blocky Minecraft counterpart.
Beyond the core structure, the free Minecraft map includes a surface area with rivers, houses, and neighborhoods. This helps players understand how G-Cans safeguards communities. You can also enter the control room and simulate diverting floodwater into the shafts to see the system in action.
MLIT developed this Minecraft version of G-Cans to raise public awareness about the facility’s vital role in disaster mitigation. Exploring it, even virtually, provides a tangible sense of the structure's immense scale. In reality, the concrete tunnels of G-Cans stretch for over 6 kilometers beneath Saitama Prefecture. Its five intake shafts collect overflow from rivers prone to flooding during Japan's rainy season in June and typhoon season around September. This water is then gradually released into the larger Edogawa River and Tokyo Bay. Since its completion in 2006 after more than a decade of construction, G-Cans has been crucial in managing flood risks for the region.
The G-Cans Minecraft map is available for free download from the official website of the Edogawa River Office, the body responsible for managing the facility. You will need Minecraft Bedrock Edition version 1.21.1 or newer, or Minecraft Education Edition version 1.21.0 or newer to play.
