France Patafisik · CC BY-SA 4.0
The descent
The entrance, at 170 m.
The real relief above Caves of Thaïs, 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.
170m
Entrance altitude
from the 30 m relief model
13°C
Inside, all year
the yearly average outside, at the entrance
378m
Rock above
the highest point within 1.5 km
Inside and outside
13 °C inside, all year.
Deep inside, a cave keeps the average temperature of the year outside: about 13 °C here, in January and in August. In July the afternoon reaches 30 °C at the entrance, 17 °C warmer than inside: take a jacket. The best months to escape the heat are from July to August. The wettest months are from October to November: water rises fast underground, so never go in without a guide after heavy rain.
- 7°0°Jan
- 9°0°Feb
- 13°3°Mar
- 18°6°Apr
- 21°10°May
- 26°15°Jun
- 30°17°Jul
- 29°16°Aug
- 24°12°Sep
- 19°8°Oct
- 12°4°Nov
- 8°0°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 France
Caves of Thaïs is a show cave in France. The entrance is at 170 m. It has an underground river and stalactites and stalagmites. It is open to visitors.
Getting there.
- Show cave: open to visitorsUsually with a guided tour; check times and tickets on the official site.
- Saint-Just-de-Claixnearest town · 3.4 km in a straight line
- Parking 60 m awaynearest car park in OpenStreetMap, straight line
- Acqueduc de Saint-Nazaire-en-Royansnearest viewpoint · 0.0 km from the entrance
- Grenoble Alpes Isère Airport (GNB)nearest airport with scheduled flights · 34 km in a straight lineCar hire at GNB airport (Grenoble)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.
The water
The Canal de la Bourne runs highest from November to December.
The Canal de la Bourne carries about 11 m³/s on average here. It runs highest from November to December.
- 7.5 m³/sJan
- 6.7 m³/sFeb
- 8.6 m³/sMar
- 8.7 m³/sApr
- 8.8 m³/sMay
- 5.7 m³/sJun
- 3.4 m³/sJul
- 2.9 m³/sAug
- 5.2 m³/sSep
- 10 m³/sOct
- 14 m³/sNov
- 11 m³/sDec
From about 2.9 m³/s in the lowest month to 14 m³/s in the highest. Its basin above this point covers 708 km².
Follow the Isère from source to mouth on Riveryas
Estimate: long-term flow from the HydroATLAS model (WaterGAP, 1971–2000) shaped by the monthly rain, snow and temperature of the area (NASA POWER). Dams change it. Not a forecast.
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.
- 2other cave entrances within 3 kmGrotte de Thaïs
- 1caving clubs and spots within 15 kmLa Fabrik Vertaco
- 8viewpoints within 3 kmAcqueduc de Saint-Nazaire-en-Royans, Belvédère, Vue sur l'Aqueduc and 5 more
- 63marked hiking routes within 3 kmL'Hostunoise and 62 more
- 32car parks within 2 km
- 20information boards and visitor centres within 3 km
- 26bus stops within 2 km
- 11campsites within 8 kmLes Carrets, Le pont de Manne, Aire de Camping-Car Vercors Noix and 8 more
- 9hotels and guesthouses within 8 kmHôtel du Musée, Hôtel du Royans, Beau Rivage and 6 more
- 8restaurants and cafés within 3 km
- springs within 2 km
- sinkholes within 3 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
- Saint-Just-de-Claix3.4 km in a straight line
- Saint-Hilaire-du-Rosier4.4 km in a straight line
- Saint-Lattier4.6 km in a straight line
- Saint-Jean-en-Royans5.8 km in a straight line
- Saint-Laurent-en-Royans7.3 km in a straight line
- Pont-en-Royans7.4 km in a straight line
- Saint-Romans8.4 km in a straight line
- Saint-Paul-lès-Romans9.0 km in a straight line
In our other atlases
What else is around Caves of Thaïs.
The river at the entrance, the waterfalls, the lakes, the mountains and volcanoes above, the canyons, beaches and islands nearby — from our other atlases.
Peakyas2 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 | 7 | 9 | 13 | 18 | 21 | 26 | 30 | 29 | 24 | 19 | 12 | 8 |
| Afternoon | 7 | 9 | 13 | 18 | 21 | 26 | 30 | 29 | 24 | 19 | 12 | 8 |
| Night | 0 | 0 | 3 | 6 | 10 | 15 | 17 | 16 | 12 | 8 | 4 | 0 |
| Rain (mm) | 54 | 46 | 53 | 62 | 78 | 57 | 54 | 56 | 69 | 92 | 101 | 60 |
| Rainy days | 10 | 8 | 9 | 11 | 12 | 10 | 9 | 8 | 8 | 11 | 11 | 11 |
| Sun hours/day | 2.7 | 4.0 | 5.8 | 6.9 | 7.4 | 9.4 | 9.8 | 8.6 | 7.0 | 4.7 | 2.9 | 2.3 |
| Snow on the ground (cm) | 12 | 11 | 5 | 2 | 1 | 0 | 0 | 0 | 0 | 1 | 5 | 9 |
| Afternoon | Afternoon | Night | Rain (mm) | Sun hours/day | |
|---|---|---|---|---|---|
| Jan | 7 | 7 | 0 | 54 | 2.7 |
| Feb | 9 | 9 | 0 | 46 | 4.0 |
| Mar | 13 | 13 | 3 | 53 | 5.8 |
| Apr | 18 | 18 | 6 | 62 | 6.9 |
| May | 21 | 21 | 10 | 78 | 7.4 |
| Jun | 26 | 26 | 15 | 57 | 9.4 |
| Jul | 30 | 30 | 17 | 54 | 9.8 |
| Aug | 29 | 29 | 16 | 56 | 8.6 |
| Sep | 24 | 24 | 12 | 69 | 7.0 |
| Oct | 19 | 19 | 8 | 92 | 4.7 |
| Nov | 12 | 12 | 4 | 101 | 2.9 |
| Dec | 8 | 8 | 0 | 60 | 2.3 |
Averages 1991–2020 (NASA POWER) for a cell about 55 km wide, brought to the altitude of the entrance (170 m) with the standard lapse rate. Not a forecast.
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 | 49% | 62% | 90% | 70% | 88% | 145% | 21% | 106% | 96% | 122% | 31% | 189% |
| 2021 | 132% | 76% | 39% | 126% | 147% | 123% | 178% | 71% | 101% | 117% | 67% | 152% |
| 2022 | 35% | 58% | 42% | 58% | 31% | 116% | 18% | 86% | 151% | 47% | 135% | 187% |
| 2023 | 39% | 20% | 92% | 65% | 83% | 152% | 41% | 65% | 71% | 147% | 92% | 147% |
| 2024 | 100% | 122% | 263% | 100% | 167% | 148% | 109% | 42% | 168% | 122% | 29% | 85% |
| 2025 | 122% | 49% | 68% | 67% | 47% | 45% | 69% | 55% | 104% | 66% | 58% | 61% |
130% or more: wet month 70% or less: dry month
Caves nearby.
Caves of Thaïs
France
- —Depth
- —Galleries
- 170 mEntrance altitude
- 13 °CInside, all year
Choranche cave
France · 12 km
- —Depth
- —Galleries
- 725 mEntrance altitude
- 10 °CInside, all year
Gouffre Berger
France · 33 km
- —Depth
- —Galleries
- 1,458 mEntrance altitude
- 5 °CInside, all year
Where these figures come from
| Name, type, published depth and length, visitors | Wikidata (Q3117174) · 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 |
| River flow and basin | HydroATLAS / RiverATLAS v1.0 (Linke et al. 2019) · CC BY 4.0 |
| 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 
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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