A day in the depths of Piton de La Fournaise

A hike to explore the secret lava tunnels of Reunion Island
  • Intensely Volcanic
  • The volcano
Meet Julien

And discover secret tunnels…

Reunion Island is

Reunion Island!

Your perfect day

Having a good time doing “outdoor sports” with friends/famil.

Your favourite place

Trou de Fer for the atmosphere

Your passion  

Wild nature

Your favourite dish

Duck curry and “bredes chouchou” (local greens)

Your favourite artist

Mystic Man for his natural spirit and authenticity

Today we are plunging into the depths of Piton de la Fournaise, an active volcano located in the south-east of Reunion Island! For the occasion, we’re meeting Julien, a potholing guide, at the Pas de Bellecombe-Jacob viewpoint. Our programme includes hiking in the Enclos Fouqué, the caldera at the foot of Reunion’s volcano, and a potholing exploration of two lava tunnels whose whereabouts remains our guide’s well-kept secret… We’re ready, may the adventure begin!


A hike in the Piton de la Fournaise caldera in the south-east of Reunion Island

When we arrive at the Pas de Bellecombe-Jacob, Julien gives us a bag to carry our potholing equipment (harnesses, helmets and knee pads). It’s a glorious day and we can see, right before us, the small Formica Léo crater and the much more impressive Dolomieu crater. Actually there are already some hikers on their way up!


Our hike begins with a flight of steps that lead us down into the caldera of the volcano of Reunion Island. It’s a pleasant descent offering lots of beautiful views. We then leave the trail to the top of Piton de la Fournaise and follow our guide along an alternative route. The rough ground starts to crack beneath our feet. We are surrounded by outstanding scenery. We feel alone in the world, like true explorers who have just landed on the Moon! After an hour or so of walking, Julien invites us to gear up. This is where we leave the official trail. Our underground exploration of the secret lava tunnels of Piton de la Fournaise is about to begin!


Exploration of the secret lava tunnels

Julien is a guide with a passion. As we progress, he explains how the lava tunnels of Reunion Island were formed. After walking off the trail for a few minutes, we come to an impressive cavity. It is the entrance to the first lava tunnel. Julien prepares us for a rope equipment descent and we make our way carefully down into the depths of Piton de la Fournaise… As we explore beneath the surface, we notice that some of the tunnel walls are covered in a layer of white magnesite, while others display various tones of ochre. It’s a fascinating scene. We feel very lucky to be discovering these natural features that so few people get to see. The spacious cavities make it easy to progress. At the end of the lava tunnel, we find ourselves in a small basalt niche. We stop for a while as Julien takes the time to tell us some of the site’s secrets… But we can’t hang around as another adventure awaits us!


As we emerge from this first tunnel, we’re dazzled by the daylight. We had eventually got used to the darkness, the coolness and the silence! After a well-deserved picnic break, our guide takes us to discover another of nature’s gems. 


Just a few minutes’ walk from the first lava tunnel, we come to an even more impressive cavity. Julien secures a rope and this time we abseil down into the bowels of Piton de la Fournaise! Once inside, we see a magical sight. There’s much more basalt here and the light of our head torches reveals a spectacular array of minerals. There’s so much to take in, we stand in awe at the amazing decor. The volcanic rock here, everywhere, is an intense black. We continue, still quite easily, although in some places we have to crawl on all fours but without difficulty. There are stalactites above our heads, some of which reach nearly a metre in length! This second lava tunnel is bigger and complements the first one perfectly.


Both are unique and we understand why Julien never stops saying that the best is to come… It’s true! And that just about sums up our day in the bowels of Piton de la Fournaise, in the south-east of Reunion Island. A unique and memorable adventure, full of amazing natural discoveries! We leave the site, well aware of how fortunate we are to be among the privileged few who have explored these natural gems, a heritage to be preserved…

A whole day in a magical place.

Preserved tunnels.

A day excursion supervised by a qualified potholing guide whose biodiversity expertise has won him the Esprit Parc National seal of approval.