Visiting the G-Cans
Rules of the visit
A guided tour departs every hour between 10 am - 4 pm seven days a week. Reservations are necessary as only 50 people are admitted for each tour. Explanations are offered only in Japanese and for safety reasons, if you do not speak Japanese it is necessary for you to be accompanied by a Japanese speaking person.
Reservations can now be made from this below site, also available in English.
There is a charge of 1,000 JPY per person for the standard tour. The extended versions will have a different fee. There is the option to pay by credit card in advance or in person (Cash only) on the day of tour.
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 (Jan 2024)
The privately run bus service from Minami Sakurai station ceased operation at the end of 2020.
The city of Kasukabe continues to run a very limited number of services 6 days a week, excluding Sundays. The buses have limited capacity and is intended mainly for locals, though anyone is permitted to use them. IC Cards such as PASMO or SUICA accepted for payment.
PDF in Japanese with route and timetable
https://www.city.kasukabe.lg.jp/material/files/group/41/231228_showatiku.pdf
Finding a taxi at Minami Sakurai could be difficult as only a limited number of vehicles are always waiting. Consider installing the GO taxi app to catch a vehicles that is running nearby. Since late 2023, the app is available for use by non-Japanese residents also and the interface includes options for English.
Information on how to access by car or on foot can be found on the below website (in Japanese and English)
https://www.ktr.mlit.go.jp/edogawa/edogawa00165.html
What you can see in your visit
Arrive at least 10 minutes before the scheduled start of the tour. Registration is 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 on your arrival.
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.
In-depth tours
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)