Rules of the visit
Starting August 2018, there are more opportunities to view the tunnel, with a tour departing every hour between 10 am - 4 pm seven days a week. Previously visits were only possible on weekdays. Reservations are still necessary as only 50 people are admitted for each tour. Explanations continue to be offered only in Japanese and for safety reasons, it is necessary to bring along an interpreter if you do not speak Japanese.
Reservations can now be made from this below site, also available in English.
Previously visits were free but now the facility has started to charge a fee. The payment will be in cash to the staff on your arrival at the site.
What is the G Cans Project?
The G Cans Project is officially called the Metropolitan Area Outer Underground Discharge Channel. Located in Kasukabe city, a suburb to the north of Tokyo, it is a tunnel that is over 6 kilometers long and built about 50 meters underground. In case of a strong rainstorm, excessive water will enter the channel to prevent flooding to the area. Once the rains are gone, the water will be pumped out to a major river nearby. As long as there is dry weather and the channel is not used for its main purpose, the place is open for visits though reservation is a must. It is necessary to have at least one Japanese-speaking person in the group, who will be able to understand the directions from the staff in case of an emergency. Participants also need to be fit to handle the 100 steps to go down to the tunnel.
How to get there
It will take at least an hour or more to reach the place from central Tokyo. If you are staying in western Tokyo (Shibuya, Shinjuku, Ikebukuro), take the JR Shonan-Shinjuku Line to Omiya then switch to the Tobu Urban Park Line and get off at Minami-Sakurai Station. The Japan Rail Passes doesn't work for Tobu trains.
If you are staying on the central or eastern side, it might be easier to take the Metro Hanzomon Line and find the train that extends directly to the Tobu Line. Trains with destinations such as Kuki or Minami Kurihashi will take you in that direction. Change to the Urban Park Line at Kasukabe and get off at the second stop, Minami-Sakurai.
From Minami Sakurai you can catch a taxi from the northern side of the station and ask the driver to take you to the Ryukyukan ("龍Q館"）, the other name for this facility. The ride will take about 10 minutes and 1,300 JPY. If you are ok with walking, it will be about 30 minutes from the station (2.3 kilometers).
Update on access (2022)
The regularly scheduled bus service from Minami Sakurai is no longer running. The service operated by the Heisei Enterprise Group ceased operation at the end of 2020. The Kasukabe city continues to run a very limited number of services several times a week, intended mostly for use by local residents.
Finding a taxi at Minami Sakurai could be difficult as only a limited number of vehicles are available. Also consider taking one from Kasukabe Station West Exit, where there is always a car waiting. Expect the price to be around 3,500 JPY due to the longer distance of about 8.5km.
Information on how to access by car or on foot can be found on the below website (in Japanese and English)
What you can see in your visit
Arrive at least 10 minutes before the scheduled start of the tour. As of summer 2021, registration was on the ground level immediately upon entering. If you didn't make an online payment, you can pay the tour fee directly to the staff when registration.
In the standard 60 minute tour held everyday, the staff will explain the features of the facility before taking the steps down to the massive storage tank. There will be about 10-15 minutes for participants to freely take photos.
A few times a month, the facility offers extended programs which either allows a walk down one of the vertical shafts or access to the heart of the facility; the turbines and pumps.
"Pit experience course"
This allows visitors to walk partly down the vertical shafts which are 70 meters deep. Like the standard course, a visit of the storage tank is also included.
The 2 hour tour costs 3,000 JPY per person and is limited to 20 participants.
"Pump proficiency course"
This 2 hour tour allows a close-up look of the gas turbine and the four pumps which have the capacity of pumping out water from a standard sized swimming pool in just a second. There is also a trip to the water storage tank just like the other tours.
The cost is 2,500 JPY per person, with a limit of 20 participants and held only a few times a month.
Starting Aug 2021: New tour to take a look at the impeller
There is a new tour that will take visitors further into the storage tank, and allowing the view of the pump impeller that sends the water out to the Edogawa River.
The 2 hour tour costs 4,000 JPY per person and will be limited to 20 participants and held 2-3 times a week. The fee includes rental of hip waders and a helmet.
The water will be coming up to your knees, and quite an adventurous experience!
Find complete information about the different tours in this website (in Japanese)
How can I get in touch with a Japanese-English interpreter to accompany me?
Getting in touch with a volunteer guide group might be the most inexpensive way. You will be expected to cover the transport fee and perhaps maybe lunch, depending on the timing. The initial contact will need to be made well ahead of your visit, since these groups usually do not have a full-time staff that can quickly respond to inquiries. We regret to advise that we do not have any connections with any of these organizations and will not be able to assist you in finding one.