Subterranean flood water diversion channel with towering concrete columns and dramatic lighting.
Inside the impressive Subterranean Flood Water Diversion Channel, showcasing towering concrete columns and dramatic lighting.

G-Cans : Japan’s Underground Temple

Hidden below the Tokyo streets is a true superhero – a bitumen-washed facility with state-of-the-art technology and an architectural beauty to put a Corbusier or two in the shade. This is G-Cans, also known by the unlikely name of Metropolitan Area Outer Underground Discharge Channel.

architecture, japan, japanese, kanto, saitama, special, underground

But it’s not just a pretty face! It’s an underground water storage tank, part of a titanic floodwater diversion facility. This is the biggest reservoir, but it’s not the only one. It’s the culmination of a series of five huge silos with a connecting tunnel extending over 6 kilometres.

architecture, japan, japanese, kanto, saitama, special, underground

I’ll try to explain the system simply for anybody interested. The outskirts of Tokyo to the north are criss-crossed with rivers and streams. In times of heavy rainfall, this densely urbanized zone has always been subject to extensive flooding, very costly to deal with. A solution had to be found, and this is it.

architecture, japan, japanese, kanto, saitama, special, underground

Beyond this last reservoir is the Edo River. On the other side are the silos – interconnected of course. These absorb floodwater from the other rivers in the surrounding area and gradually feed it down through the tunnel to the storage tank where we stand.

architecture, japan, japanese, kanto, saitama, special, underground

The water flows relatively slowly towards this reservoir, to be stored then gradually pumped into the Edo River by 14,000-horsepower turbines.

architecture, japan, japanese, kanto, saitama, special, underground

In fact the facility is only in use between June and November, roughly between the rainy and the typhoon season.

architecture, japan, japanese, kanto, saitama, special, underground

The rest of the time, the site is open to the public and entry is even free. But there’s no denying access is difficult from Tokyo and there’s little else to visit nearby.

architecture, japan, japanese, kanto, saitama, special, underground

By the way, after you’ve seen the exhibition and video, the actual tour is extremely short. You’re only allowed to explore the inside of the storage tank for ten minutes.

architecture, japan, japanese, kanto, saitama, special, underground

All the photos posted here were taken in that time. Best be prepared! 🙂

architecture, japan, japanese, kanto, saitama, special, underground

And this is the only entrance (and exit) to the “Underground Temple”. Imagine all that really lies beneath our feet, especially in the big cities …

architecture, japan, japanese, kanto, saitama, special, underground

For security reasons, visitors must speak Japanese or be accompanied by someone who does. You also need to book well in advance via the official website. For more information visit the G-Cans English page.

If you like impressive, extraordinary structures, have a look at my articles on  Gunkanjima, of course,  the awesome Super-Kamiokande, as well as that strange Tokyo building, the Nakagin Capsule Tower.

And for more awesome content about Japan, follow Jordy Meow on Instagram ! 🎵

Who Am I

Jordy Meow
This is me!

I am Jordy Meow, a French photographer based in Tokyo. I explore offbeat places in Japan.

Instagram

A captivating night scene in Japan where ancient traditions meet modern city lights. This balance of the old and new is what makes urban life here so unique and beautiful. 静かな夜、日本の都市で古と現代の光が交わる情景。この古と新の調和が、ここ日本の都市の魅力を引き立てます。 #UrbanJapaneseNights #TraditionMeetsModern #NeonAndLanterns #TokyoVibes #CulturalContrast #OffbeatJapan #Japan
From the weathered castle roof, witness the timeless beauty of Japan as a quaint town rests peacefully amid rolling hills and a golden sky. 🌄🏯---古びた城の屋根から、静かに横たわる谷の町と黄金の空を背景に見渡す日本の時を超えた美しさ。🌄🏯---#offbeatjapan #japan #castleviews #historicjapan #sunsetmagic #explorehistory #tranquility
A pop of color brightens the roadside with this charming fruit-shaped bus stop, showcasing Naoshima's unique blend of art and practicality, where every corner holds a piece of its creative spirit.カラフルなフルーツ型のバス停が道端を彩ります。直島では、アートと実用性が見事に融合し、創造的なスピリットがあちこちに漂っています。#Naoshima #offbeatjapan #artisland #creativebusstop #uniquearchitecture #tangerinedream #japan
Lost in time on this charming street, where history, traditional architecture, and stunning nature merge beautifully. Discover the heart of Japan’s ceramic artistry and its serene beauty.---歴史、伝統的な建築、そして美しい自然が見事に調和するこの魅力的な通りで、時を忘れる。日本の陶芸とその静かな美しさを発見してみてください。---#ceramics #history #traditionaljapan #architecture #nature #offbeatjapan #japan
Step through the iconic red torii gate into a serene, sacred space where nature and spirituality meet in harmony, a beautiful embodiment of Japan's Shinto traditions. 🌿🇯🇵 #NatureLovers --- 赤い鳥居をくぐり、自然と精神性が調和する静かな聖域へ。日本の神道の伝統を美しく体現しています。🌿🇯🇵 #自然愛好家--- #offbeatjapan #japan #shinto #torii #sacredspace #nature #spirituality #forestpath
Witness Tokyo's dazzling evening skyline with Mount Fuji's silhouette gracing the horizon—a perfect blend of urban energy and natural beauty. 🌆🌸---富士山のシルエットが地平線を飾る、東京の華やかな夜景の眺め。都市のエネルギーと自然の美しさが見事に調和しています。🌆🌸---#TokyoNights #MountFuji #CityscapeLove #JapanViews #UrbanBeauty #OffbeatJapan #Japan
Discover the beauty of Japan's countryside where ancient traditions meet modern life. The vibrant fields and serene landscapes remind us of nature's harmony and human artistry.日本の田舎の美しさを発見しましょう。伝統と現代が出会う場所です。鮮やかな田んぼと静かな景色が、自然の調和と人の技を思い出させてくれます。#RuralEscape #NatureAndCulture #ScenicJapan #JapaneseCountryside #offbeatjapan #japan #HiddenGemsJapan
Lost in the misty embrace of Japan's mountains, this hidden village showcases the stunning connection between human life and nature. 🌿🏡日本の山々の霧に包まれたこの隠れ里は、人間と自然の美しい共存を見せてくれます。🌿🏡#MistyMountains #HiddenVillage #RuralJapan #NatureAndCulture #MountainLife #OffbeatJapan #Japan