Tokyo G-CANS Travel Guide

The story

A flood tunnel you can walk into

G-CANS is the Metropolitan Area Outer Underground Discharge Channel in Kasukabe, Saitama, a flood-control system whose huge pressure-control tank is nicknamed the underground temple.

It is a working piece of infrastructure, so tours run only when the facility is not in operation and can be changed or cancelled when it is.

60 minshortest tour, the Underground Temple Course

10:00-16:00hours listed for the facility

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Practical guide

Plan your Tokyo G-CANS trip

Check before you go: reservations are required and are made through the official website. Tours can be changed or cancelled when the facility is operating, so confirm dates before you travel.

Tour options

The Underground Temple Course lasts 60 minutes, the Shaft Experience Course 110 minutes and the Impeller Exploration Course 110 minutes.
All courses include a lecture on the system and a visit to the pressure control tank.
Fees listed by a Japan travel directory are 1,200, 3,500 and 4,500 yen respectively. Confirm on the official site.

Reservations

Reservations are required through the official website, and on the day they are accepted until 10 minutes before the course starts.
Credit cards are not accepted at the facility. Web payment is available.
The page does not say which tour languages are offered, so check before you reserve.

Getting there

The visitor centre, Ryu Q Kan, is at 720 Kamikanasaki, Kasukabe City, Saitama.
Take a taxi for about 7 minutes from Minami Sakurai Station on the Tobu Noda Line, or the Kasukabe city community bus, which runs a few times a day.
Taxis at Minami Sakurai are limited, so many visitors reserve a taxi ahead or take a taxi from Kasukabe Station. Sources disagree about the bus, so verify.

Good to know

You need to be able to walk about 100 steps on your own.
The facility is closed on certain days for inspections, and tours are offered when it is not in operation, usually only a few times a year.

Details come from a Japan travel directory and may change. The official G-CANS website is the source to trust for dates and fees. We checked on November 1, 2026. Entry rules, fees and prices change, so confirm them with official sources before you reserve.