The Japanese government has unveiled a detailed Minecraft map of the world’s largest underground flood prevention facility — the Metropolitan Area Outer Underground Discharge Channel, affectionately known as G-Cans. This immersive and educational recreation allows players to explore one of Tokyo’s most visually stunning yet lesser-known landmarks from anywhere in the world, all at no cost.

G-Cans is best recognized for its awe-inspiring “pressure adjustment water tank,” a vast subterranean chamber supported by 59 colossal pillars. Often referred to as the “underground temple” (*chika shinden*) in Japan, this location has inspired music videos, TV dramas such as *Kamen Rider*, and even major motion pictures. With its dramatic architecture and cinematic atmosphere, it's easy to imagine it as the final boss arena in an epic game.

The real-life G-Cans. Photographer: Tomohiro Ohsumi/Bloomberg via Getty Images

While physical tours are available during dry seasons, the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) now offers a virtual alternative through Minecraft. The ministry has also published a video on their official YouTube channel that explains the function of G-Cans and showcases how it appears in the blocky world of Minecraft.

This free Minecraft map doesn’t just recreate the underground structure — it includes a surface area with rivers, homes, and neighborhoods, giving players a broader understanding of how G-Cans protects populated areas from flooding. You can even step into the control room and simulate draining excess rainwater into the massive underground shafts, experiencing firsthand how this engineering marvel operates.

The Minecraft G-Cans. Image credit: the Edogawa River Office

MLIT designed this Minecraft project with education in mind, aiming to raise awareness about flood prevention and disaster preparedness. By exploring G-Cans virtually, players gain a deeper appreciation for its sheer scale. In reality, G-Cans features over 6 kilometers of concrete tunnels running beneath Saitama Prefecture, part of the Greater Tokyo Area. During Japan’s rainy season in June and typhoon season in September, the system collects excess water from vulnerable rivers and gradually releases it into the Edogawa River and Tokyo Bay. Completed in 2006 after more than a decade of construction, G-Cans has since played a crucial role in protecting the region from catastrophic floods.

The G-Cans Minecraft map is available for free download via the Edogawa River Office official website. Please note that you’ll need at least Version 1.21.1 of Minecraft Bedrock Edition or Version 1.21.0 of Minecraft Education Edition to run the map properly.