Japan Lava tube
Lake Sai Bat Cave
10 °C inside, all year.
Sakaori ( talk ) · CC BY-SA 3.0
The descent
The entrance, at 938 m.
The real relief above Lake Sai Bat Cave, measured on the Copernicus model every 30 m, and the cave going down at the same vertical scale.
The depth is the one published by those who explored it; the shape of the galleries is a sketch, not a survey. No depth has been published for this cave yet.
938m
Entrance altitude
from the 30 m relief model
10°C
Inside, all year
the yearly average outside, at the entrance
295m
Rock above
the highest point within 1.5 km
Inside and outside
10 °C inside, all year.
Deep inside, a cave keeps the average temperature of the year outside: about 10 °C here, in January and in August. In August the afternoon reaches 26 °C at the entrance, 17 °C warmer than inside: take a jacket.
- 2°-7°Jan
- 4°-6°Feb
- 8°-3°Mar
- 14°2°Apr
- 19°8°May
- 22°13°Jun
- 26°17°Jul
- 26°18°Aug
- 22°14°Sep
- 17°8°Oct
- 11°1°Nov
- 5°-4°Dec
Outside: afternoon and night averages for 1991–2020 (NASA POWER) brought to the altitude of the entrance. Inside: the yearly average, which deep parts of a cave keep. Near the entrance it follows the weather a little.
Cave in Japan
Lake Sai Bat Cave is a lava tube in Japan. The entrance is at 938 m. It has an underground lake and the shape of a lava tube.
Getting there.
- Wild cave: only with caving equipmentNo paths or lights inside. Go only with a caving club or a qualified guide.
- Fujikawaguchikonearest town · 1.5 km in a straight line
- 三湖台nearest viewpoint · 1.0 km from the entrance
- Mount Fuji Shizuoka Airport (FSZ)nearest airport with scheduled flights · 89 km in a straight lineCar hire at HND airport (Tokyo)Discover Cars · sponsored link↗
Plan the visit
Guided tours, a bed nearby, a car.
Some links above are affiliate links: if you book through them we may earn a commission, at no extra cost to you. It never changes what the data on this page says.
From above.
The ground above the cave, with the relief shaded, the line of the section and what people have mapped around the entrance.
N
1.5 km
Sentinel-2 cloudless 2016 (EOX, CC BY 4.0), 6.0 × 6.0 km, north up. The line is the section above. Points © OpenStreetMap contributors.
Around the entrance.
- 4other cave entrances within 3 km鳴沢氷穴, 竜宮洞穴, 富岳風穴 and 1 more
- 5viewpoints within 3 km三湖台, いやしの里 根場, 鍵掛峠 and 2 more
- 2marked hiking routes within 3 km東海自然歩道, 自然探索路
- 23car parks within 2 km
- 27information boards and visitor centres within 3 km
- 23bus stops within 2 km
- 8campsites within 8 km本栖湖スポーツセンター キャンプサイト, 本栖湖キャンプ場, 本栖レークサイドキャンプ場 and 5 more
- 52hotels and guesthouses within 8 kmくわるび, 泰平館, 旅館 梨館温泉 and 49 more
- 12restaurants and cafés within 3 km
- springs within 2 km
- sinkholes within 3 km
- caving clubs and spots within 15 km
- climbing crags within 3 km
- named waterfalls within 4 km
Counted in OpenStreetMap, the map anyone can edit, around the entrance. A low number may just mean nobody has mapped it yet. © OpenStreetMap contributors (ODbL).
Towns nearby
- Fujikawaguchiko1.5 km in a straight line
- Narusawa2.8 km in a straight line
- Fujiyoshida13 km in a straight line
- Fuefuki16 km in a straight line
- Onuma16 km in a straight line
- Oshino17 km in a straight line
- Ichikawadaimon18 km in a straight line
- Isawa18 km in a straight line
In our other atlases
What else is around Lake Sai Bat Cave.
The river at the entrance, the waterfalls, the lakes, the mountains and volcanoes above, the canyons, beaches and islands nearby — from our other atlases.
Lakeyas4 lakes within 10 km
Peakyas15 mountains within 10 kmFigures from the sister sites' databases (Wikidata, HydroATLAS, GeoNames, NOAA, OpenStreetMap). Links open when each site is online.
Month by month
The weather outside, at the entrance.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Afternoon | 2 | 4 | 8 | 14 | 19 | 22 | 26 | 26 | 22 | 17 | 11 | 5 |
| Afternoon | 2 | 4 | 8 | 14 | 19 | 22 | 26 | 26 | 22 | 17 | 11 | 5 |
| Night | -7 | -6 | -3 | 2 | 8 | 13 | 17 | 18 | 14 | 8 | 1 | -4 |
| Rain (mm) | 61 | 71 | 115 | 127 | 140 | 174 | 209 | 159 | 201 | 193 | 85 | 64 |
| Rainy days | 6 | 7 | 10 | 10 | 13 | 16 | 18 | 17 | 15 | 11 | 8 | 7 |
| Sun hours/day | 6.1 | 6.1 | 6.1 | 6.2 | 6.1 | 4.2 | 4.5 | 5.6 | 4.6 | 4.6 | 5.4 | 5.8 |
| Snow on the ground (cm) | 14 | 14 | 10 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 11 |
| Afternoon | Afternoon | Night | Rain (mm) | Sun hours/day | |
|---|---|---|---|---|---|
| Jan | 2 | 2 | -7 | 61 | 6.1 |
| Feb | 4 | 4 | -6 | 71 | 6.1 |
| Mar | 8 | 8 | -3 | 115 | 6.1 |
| Apr | 14 | 14 | 2 | 127 | 6.2 |
| May | 19 | 19 | 8 | 140 | 6.1 |
| Jun | 22 | 22 | 13 | 174 | 4.2 |
| Jul | 26 | 26 | 17 | 209 | 4.5 |
| Aug | 26 | 26 | 18 | 159 | 5.6 |
| Sep | 22 | 22 | 14 | 201 | 4.6 |
| Oct | 17 | 17 | 8 | 193 | 4.6 |
| Nov | 11 | 11 | 1 | 85 | 5.4 |
| Dec | 5 | 5 | -4 | 64 | 5.8 |
Averages 1991–2020 (NASA POWER) for a cell about 55 km wide, brought to the altitude of the entrance (938 m) with the standard lapse rate. Not a forecast.
Photographs
Inside and around.
Recent years
Wet years, dry years.
Rain of each month as a share of the 1991–2020 average. A dry year means a lower river and hotter rock; a wet one, more water in the gorge.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2020 | 152% | 74% | 121% | 127% | 71% | 142% | 257% | 35% | 83% | 126% | 26% | 26% |
| 2021 | 135% | 87% | 139% | 92% | 121% | 82% | 162% | 204% | 92% | 55% | 84% | 138% |
| 2022 | 31% | 72% | 85% | 171% | 111% | 81% | 143% | 144% | 151% | 50% | 115% | 58% |
| 2023 | 31% | 70% | 115% | 105% | 168% | 244% | 43% | 122% | 85% | 64% | 87% | 54% |
| 2024 | 71% | 185% | 176% | 112% | 182% | 194% | 67% | 290% | 69% | 124% | 163% | 5% |
| 2025 | 44% | 21% | 132% | 99% | 163% | 93% | 78% | 54% | 125% | 84% | 26% | 76% |
130% or more: wet month 70% or less: dry month
Caves nearby.
Lake Sai Bat Cave
Japan
- —Depth
- —Galleries
- 938 mEntrance altitude
- 10 °CInside, all year
Narusawa Ice Cave
Japan · 2 km
- —Depth
- —Galleries
- 1,039 mEntrance altitude
- 0 °CInside, all year
Fugaku Wind Cave
Japan · 2 km
- —Depth
- —Galleries
- 1,012 mEntrance altitude
- 0 °CInside, all year
Where these figures come from
| Name, type, published depth and length, visitors | Wikidata (Q11629114) · CC0 |
|---|---|
| The relief above, the entrance altitude, the section and the 3D model | Copernicus DEM GLO-30 · © DLR e.V., © Airbus Defence and Space GmbH, Copernicus/ESA |
| Climate | NASA POWER, 1991–2020 |
| Entrances, springs, sinkholes, opening hours and what is around | © OpenStreetMap contributors · ODbL |
| Images | EOX Sentinel-2 cloudless 2016 · CC BY 4.0; Wikimedia Commons |
| Rivers, waterfalls, lakes, mountains, canyons, beaches and islands nearby | Coastya, Lakeyas, Peakyas, Cascadyas, Islandyas, Riveryas |
Every figure is an average, an estimate or a count from a public dataset. Licences and methods: data sources.
The family
Do you prefer beaches, lakes, mountains, waterfalls, islands, rivers, canyons, caves, dark skies, viewpoints, birdwatching or forests?
Same idea, other landscapes: field atlases built on open data, month by month, in seven languages.
beaches
Find your beach: sea temperature, sun and swimming month by month.Visit lakes
Every lake on Earth: water temperature, ice, depth and the shore.Visit mountains
Every summit in 3D: summit weather, the 0 °C line, huts and trails.Visit 
waterfalls
Every waterfall: height, flow month by month and when it roars.Visit 
islands
Every island from the sea up: size, sea temperature, ferries and 3D.Visit 
rivers
Every river from source to sea: the journey, the flow and the basin in numbers.Visit 
canyons
Every canyon cut to scale: depth to the floor, rim and floor temperatures, trails and viewpoints.Visit 
caves
Every cave with its real depth and length: the rock above, the temperature inside all year, and how to visit.You are here
dark skies
Where the night is still dark: the sky of every place, the Milky Way month by month, the Moon, eclipses and auroras.Coming soonVisit 
viewpoints
Every viewpoint with its real 360° panorama: the peaks you can name, how far you see and where the sun sets.Coming soonVisit 
birdwatching
Every bird sanctuary and wetland with the species recorded month by month: who is resident, who comes for the summer, who only passes through.Coming soonVisit 
forests
Every forest with its land-cover rings, what grows and lives in it, and the best months to walk it.Coming soonVisit