内間木洞
Deep in the hundred-acre woods….Oh wait, different story. Let’s start again!
Hidden beneath the mountains of northern Iwate lies Uchimaki Cave (内間木洞), Japan’s fifth-longest limestone cave system, stretching more than 6.3 kilometers underground.
This is not an ordinary cave. For starters, it is not normally open to the public. It is primarily a research cave and closed to tourist traffic. But, twice a year, it is opened for a brief few days to let the public get a taste of this amazing micro-climate!
The first annual open period is in the depths of winter- February! It is COLD – not ‘a bit chilly’ but COLD. But the July ‘Uchimaki-dou festival’ is much more approachable. The outside air is hot and humid, in line with much of Japan’s summer climate, but inside the cave is refreshingly chill and much welcome relief from the summer heat!
Family-friendly access!
I can not overemphasize how accessible this place is! If you watch my YouTube short below, you will get a glimpse of the 1-month-old newborn I was carrying with me the entire visit, along with the herd of small kids that didn’t need carrying! There are steel steps and guard rails where needed, and the walls are never (well, almost never) more than arm’s length away. There is exactly one section that was a little bit slippery – a 10-meter section leading up into the upper Grand Hall that was a bit iffy. But a slip there would result in a bruised ego and muddy pants only; there is no ‘abyss’ to fall off into (at that point….). So take your kids with peace of mind!
Take a look at these videos, but don’t worry – I didn’t spoil EVERYTHING! There is plenty left that didn’t make it into the videos for you to discover!
Visit Guidance
This place is not a polished tourist site. Access is free, including the borrowing of rubber boots, helmets (required), and flashlights. If you don’t have decent shoes, borrow a set of their boots! A light jacket is needed in summer – heavy winter gear in…wait for it….winter! A typical tour will last about an hour, more if you are a spelunking enthusiast, less if you forgot your jacket! As you can see, I took our infant with NO problems, but reasonable judgment as to your group’s physical abilities is advised. There are stairs, some slippery spots, and uneven cave ground throughout. See the Google Maps link below for travel options and routes.
Restrooms and basic facilities are available in the nearby guest house. NO FACILITIES EXIST IN THE CAVE ITSELF!
But even with all that, they don’t accept a red penny (or a yen’ny!). So do take a moment after your tour to buy some of the local food offerings at the guest house. They have roasted and salted fish, miso mochi, fried tofu, yakitori, and usually an old hunter there with offerings of local deer and wild boar! Very cheap and a great way of contributing to the community!
Before I get into the language guide below, here are the official websites and the Google Maps links:
Want to Read the Japanese?
One of my favorite parts of visiting places like this isn’t just seeing them—it’s learning to read the Japanese signs that explain them.
Rather than translating word-for-word, I use a method I call chunking: breaking Japanese into natural thought groups.
Let’s try it together.
Read the Japanese
Below is a ‘chunking’ of the language used throughout this incredible natural wonder!
If this is your first exposure to ‘chunking’ for Japanese language learning, please read my post on Stop Translating. Start Thinking in Japanese first!
Chunk 1
内間木洞は総延長6,350m以上で
うちまぎどう は そうえんちょう ろくせんさんびゃくごじゅうメートル いじょう で
Uchimaki Cave has a total surveyed length of over 6,350 meters.
Grammar:
総延長
そうえんちょう
= total length
～以上で
～いじょう で
“being over…”
The で connects this fact to what follows.
Chunk 2
国内第5位の全長を誇る鍾乳洞です。
こくない だいごい の ぜんちょう を ほこる しょうにゅうどう です。
It is a limestone cave boasting the fifth-longest total length in Japan.
Grammar
国内
こくない
within Japan
第5位
だいごい
5th place
全長
ぜんちょう
overall length
～を誇る
～を ほこる
literally
to boast
Often translated more naturally as
renowned for
famous for
possesses
You’ll see this expression constantly in tourism literature.
Chunk 3
洞内の大空間である「千畳敷」や
どうない の だいくうかん である 「せんじょうじき」や
The enormous chamber called “Senjōjiki,” and…
Grammar
洞内
どうない
inside the cave
大空間
だいくうかん
large open chamber
である
Formal version of です
Used constantly in brochures.
Chunk 4
巨大な陥没孔の「洞内ドリーネ」
きょだい な かんぼつこう の 「どうない ドリーネ」
the giant sinkhole known as the “Cave Doline,”
Vocabulary
陥没孔
かんぼつこう
sinkhole
ドリーネ
“doline”
A geological sinkhole.
Borrowed scientific term.
Chunk 5
鍾乳石の連なりが
しょうにゅうせき の つらなり が
rows of stalactites
Literally
“The connected line of stalactites…”
Vocabulary
連なり
つらなり
series
chain
succession
Chunk 6
巨大な滝や山を連想させる
きょだい な たき や やま を れんそう させる
that evoke enormous waterfalls and mountains
Grammar
連想させる
れんそう させる
cause someone to imagine, remind someone of, evoke
A beautiful tourism word.
Chunk 7
「大瀑布」や「内間木富士」など
「だいばくふ」や「うちまぎふじ」など
features such as “Great Waterfall” and “Uchimaki Fuji”
Notice:
など
means: among others etc.
Chunk 8
地底で長い年月をかけて作られた
ちてい で ながい ねんげつ を かけて つくられた
formed underground over countless years
Grammar
年月をかけて
ねんげつ を かけて
over many years, taking a long time
Excellent phrase.
Chunk 9
自然の驚異を見ることができます。
しぜん の きょうい を みること が できます。
visitors can witness these wonders of nature.
Very common tourist phrase.
見ることができます
“You can see…”
Chunk 10
キクガシラコウモリを始めとする
キクガシラコウモリ を はじめ とする
including the Japanese horseshoe bat
Grammar
～を始めとする
～を はじめ とする
beginning with…
including…
headed by…
Extremely common.
Chunk 11
7種のコウモリや昆虫類など
ななしゅ の コウモリ や こんちゅうるい など
seven species of bats and various insects
Chunk 12
貴重な生き物たちも生息しており
きちょう な いきものたち も せいそく しており
valuable wildlife also inhabits the cave
Vocabulary
生息する
せいそくする
to inhabit
to live (wild animals)
Very useful word.
Chunk 13
岩手県指定天然記念物
いわてけん してい てんねんきねんぶつ
Iwate Prefecture Designated Natural Monument
Excellent vocabulary.
You’ll see this at shrines, forests, waterfalls…
everywhere.
Chunk 14
普段は研究や教育目的以外の公開はされていませんが
ふだん は けんきゅう や きょういく もくてき いがい の こうかい は されていません が
Normally, it is not open to the public except for research and educational purposes…
This is a fantastic sentence.
Chunk 15
年2回だけ一般公開されています。
ねん にかい だけ いっぱんこうかい されています。
It is opened to the general public only twice each year.
⭐⭐⭐
Chunk 16
氷筍は
ひょうじゅん は
Ice stalagmites…
Chunk 17
水滴が地面で凍りつき
すいてき が じめん で こおりつき
water droplets freeze on the cave floor
Vocabulary
凍りつく
こおりつく
to freeze solid
Chunk 18
筍状に成長したもの
たけのこじょう に せいちょう した もの
forming bamboo-shoot-shaped ice formations
Great example of
～状
-shaped
Chunk 19
大きなものは2m以上になります。
おおきな もの は にメートル いじょう に なります。
Some exceed two meters in height.
Chunk 20
神秘の世界を体感することができます。
しんぴ の せかい を たいかん すること が できます。
You can experience this mysterious world firsthand.
⭐ My favorite phrase in the entire brochure
地底で長い年月をかけて作られた自然の驚異
ちてい で ながい ねんげつ を かけて つくられた しぜん の きょうい
Literally:
The wonders of nature created underground over the course of countless years.
Final Thoughts
Uchimaki Cave is worth visiting for its geology alone.
But for me, one of the most rewarding parts of the day was bringing home a few more pieces of Japanese to study.
Every brochure.
Every trail sign.
Every museum display.
They’re all opportunities to add another handful of gravel to my own Mt. Iwate of Japanese ability.
If you’re learning Japanese too, I hope this guide helps you do the same.
Have you visited Uchimaki Cave?
Or do you have another hidden corner of northern Japan that deserves more attention?
I’d love to hear about it in the comments below.
