The Japanese government has unveiled a free Minecraft map that brings one of the world’s largest underground flood prevention facilities directly to your screen. This immersive experience allows players to explore the iconic G-Cans (Metropolitan Area Outer Underground Discharge Channel), a lesser-known yet awe-inspiring engineering marvel located in the Tokyo area, all from the comfort of home.

Officially known as the Metropolitan Area Outer Underground Discharge Channel and affectionately referred to as G-Cans, this facility plays a critical role in disaster prevention. Its most famous feature is the “pressure adjustment water tank” — an enormous cathedral-like chamber supported by 59 colossal pillars. Often dubbed the “underground temple” (chika shinden) in Japan, this dramatic space has even served as a filming location for music videos, TV dramas like Kamen Rider, and movies.

While it's possible to tour G-Cans in person during dry seasons, the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) now offers a unique digital alternative through Minecraft. The ministry has also released a video on their official YouTube channel explaining G-Cans’ purpose and showcasing its representation in the game.

This Minecraft map isn't limited to just the underground structure — it includes a detailed overground environment featuring rivers, homes, and neighborhoods. These elements help illustrate how G-Cans functions to protect communities from flooding. Players can even step into the control room and simulate draining excess rainwater into the massive underground shafts to better understand how the system operates.

MLIT developed this Minecraft recreation with education in mind, aiming to raise awareness about the importance of flood prevention infrastructure. Exploring the blocky version of G-Cans still gives players a strong sense of its immense scale. In reality, the concrete tunnels stretch more than 6 kilometers beneath Saitama Prefecture as part of the Greater Tokyo Area. During Japan’s rainy season (typically June) and typhoon season (usually September), G-Cans captures overflow from vulnerable rivers and gradually releases it into the larger Edogawa River and eventually Tokyo Bay. Completed in 2006 after more than a decade of construction, G-Cans has been instrumental in reducing flood risks ever since.

The G-Cans Minecraft map is available as a free download from the official website of the Edogawa River Office, the agency responsible for managing the facility. To play, you'll need at least Version 1.21.1 of Minecraft Bedrock Edition or Version 1.21.0 of Minecraft Education Edition.