# Metropolitan Area Outer Underground Discharge Channel, Japan: what it is and when to go

> Metropolitan Area Outer Underground Discharge Channel is a tunnel in Japan (首都圏外郭放水路) (Tokyo). Interests: Museums and art. The best time to visit is February to May and October to November. In June there are 14 h 26 of daylight, and in December, 9 h 34. It has articles in 16 Wikipedias, so it is not one of the busiest places in Japan: one to enjoy at a calmer pace. Here is what it is, where it lies, when to come, how to get there and what else is nearby to turn it into a trip.

- Address: https://kokai.app/en/paises/asia/japon/metropolitan-area-outer-underground-discharge-channel-facili/
- Reviewed on: 2026-10-02
- Language: en

## In a nutshell

- **What it is:** Tunnel in Japan · Museums and art
- **Local name:** 首都圏外郭放水路
- **Where:** Japan
- **Best time:** February to May and October to November.
- **Nearest airport:** HND Tokyo, 50 km as the crow flies
- **Opening hours:** Mo-Su 09:30-16:30
- **Coordinates:** 35.99728, 139.81173

## What it is and where

Metropolitan Area Outer Underground Discharge Channel is a tunnel in Japan (首都圏外郭放水路) (Tokyo). It has articles in 16 Wikipedias, so it is not one of the busiest places in Japan: one to enjoy at a calmer pace.

It is in [Tokyo](https://kokai.app/en/paises/asia/japon/tokio/), where this site lists 287 more places to see, 35 km from the centre.

Its coordinates are 35.99728, 139.81173; the nearest main airport is Tokyo Haneda International Airport (HND, Tokyo), 50 km as the crow flies. How to get around Japan (train, car, bus) is covered in [its country guide](https://kokai.app/en/paises/asia/japon/#moverse).

- [Where it is](https://www.google.com/maps/search/?api=1&query=35.99728%2C139.811734)
- [Directions](https://www.google.com/maps/dir/?api=1&destination=35.99728%2C139.811734)

It is one of the [Museums and art](https://kokai.app/en/paises/asia/japon/museos/) places in Japan. In [Kokai](https://kokai.app/en/) it is already on your trip map next to the places you save yourself, and it goes into a day's plan with one tap.

## When to go

The best time to visit Metropolitan Area Outer Underground Discharge Channel is **February to May and October to November**.

| Mes | Época | Hours of daylight |
| --- | --- | --- |
| January | Possible | 9 h 49 |
| February | Best time | 10 h 41 |
| March | Best time | 11 h 44 |
| April | Best time | 12 h 55 |
| May | Best time | 13 h 54 |
| June | Possible | 14 h 26 |
| July | Possible | 14 h 13 |
| August | Possible | 13 h 22 |
| September | Possible | 12 h 13 |
| October | Best time | 11 h 04 |
| November | Best time | 10 h 03 |
| December | Possible | 9 h 34 |

In June there are 14 h 26 of daylight, and in December, 9 h 34. Daylight hours are calculated from the site's latitude for the 15th of each month; when planning a full day on foot they matter as much as the weather.

When to go to Japan in general, with its festivals and peak seasons, is in [its country guide](https://kokai.app/en/paises/asia/japon/#cuando-ir).

## Before you go to Japan

To enter Japan there are 10 things to sort out before you leave, starting with “A valid passport covering your whole stay”: they are all, with their deadlines, in [the Japan checklist](https://kokai.app/en/paises/asia/japon/#antes-de-salir). Currency: Japanese yen (JPY); plugs: Type A and B · 100 V · 50/60 Hz (you need an adapter); emergencies: 110 police · 119 ambulance and fire.

In [Kokai](https://kokai.app/en/) you tick off the checklist inside your trip, and each item reminds you when it is time to do it.

## What is nearby

- [Mogi-Honke Museum of Art](https://kokai.app/en/paises/asia/japon/mogi-honke-museum-of-art/): Museum in Japan · 7.7 km
- [Uta Hot Spring](https://kokai.app/en/paises/asia/japon/uta-hot-spring/): Onsen · 9.0 km
- [Tobu Zoo](https://kokai.app/en/paises/asia/japon/tobu-zoo/): Zoo and amusement park in Japan · 9.4 km
- [Ibaraki Nature Museum](https://kokai.app/en/paises/asia/japon/ibaraki-nature-museum/): Museum in Bando, Ibaraki pref., Japan · 9.5 km
- [Chiba Prefectural Sekiyado-jō Museum](https://kokai.app/en/paises/asia/japon/chiba-prefecture-sekiyado-castle-museum/): Archive organization in Noda, Japan · 12 km

Distances are as the crow flies. Everything else is in [the Japan guide](https://kokai.app/en/paises/asia/japon/).

## More in Japan: Museums and art

- [Tokyo National Museum](https://kokai.app/en/paises/asia/japon/museo-nacional-de-tokio/): art museum in Tokyo, Japan
- [Matsumoto Castle](https://kokai.app/en/paises/asia/japon/castillo-de-matsumoto/): building in Matsumoto, Nagano Prefecture, Japan
- [National Museum of Western Art](https://kokai.app/en/paises/asia/japon/museo-nacional-de-arte-occidental/): art museum in Tokyo, Japan
- [Hiroshima Castle](https://kokai.app/en/paises/asia/japon/castillo-de-hiroshima/): Castle
- [Kōfuku-ji](https://kokai.app/en/paises/asia/japon/kofuku-ji/): Buddhist temple in Nara Prefecture, Japan
- [Ushiku Daibutsu](https://kokai.app/en/paises/asia/japon/ushiku-daibutsu/): statue located in Ushiku, Ibaraki Prefecture, Japan

Every Japan place under Museums and art, each with its season, is on [its page](https://kokai.app/en/paises/asia/japon/museos/).

## Frequently asked questions

### What is Metropolitan Area Outer Underground Discharge Channel?

It is a tunnel in Japan (首都圏外郭放水路 in the local language). It has articles in 16 Wikipedias, so it is not one of the busiest places in Japan: one to enjoy at a calmer pace.

### When is the best time to visit Metropolitan Area Outer Underground Discharge Channel?

February to May and October to November. In June there are 14 h 26 of daylight, and in December, 9 h 34.

### How do you get to Metropolitan Area Outer Underground Discharge Channel?

The nearest main airport is Tokyo Haneda International Airport (HND), 50 km as the crow flies. From there, [directions](https://www.google.com/maps/dir/?api=1&destination=35.99728%2C139.811734) opens the route on the map, and how to get around Japan is explained in [its country guide](https://kokai.app/en/paises/asia/japon/#moverse).

### How do I add it to my trip?

With one tap. In Kokai it is already on the Japan map, next to the places you save yourself: add it to a day's plan, give it a time and, if you like, get a reminder when you pass nearby.

### What else is around here?

Nearby you have [Mogi-Honke Museum of Art](https://kokai.app/en/paises/asia/japon/mogi-honke-museum-of-art/), [Uta Hot Spring](https://kokai.app/en/paises/asia/japon/uta-hot-spring/), [Tobu Zoo](https://kokai.app/en/paises/asia/japon/tobu-zoo/). The rest is in [the Japan guide](https://kokai.app/en/paises/asia/japon/).

Data from [OpenStreetMap](https://www.openstreetmap.org/node/4580690391), licensed under the ODbL, and from [Wikidata](https://www.wikidata.org/wiki/Q1887758), CC0. More about Metropolitan Area Outer Underground Discharge Channel on [Wikipedia](https://ja.wikipedia.org/wiki/%E9%A6%96%E9%83%BD%E5%9C%8F%E5%A4%96%E9%83%AD%E6%94%BE%E6%B0%B4%E8%B7%AF). Daylight hours are calculated from the latitude. More in [credits](https://kokai.app/en/aviso/#creditos).