Nez de Boeuf-Roche Plate (rivière des remparts)

Walking/pedestrian at Saint-Joseph

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15.2 km
  • Hiking in the valley of the Rivière des Remparts helps you better understand how Reunion Island was formed and the history of how the Highlands were settled. Beyond the beauty of the landscape, it’s interesting to be accompanied by someone who understands volcanism and how the region was settled to better understand the island. The hike starts at the volcano massif at the point known as Nez de Boeuf. You’ll begin to descend the ramparts to the bottom of the valley and then follow the gently sloping path that takes you to the islet of Roche Plate. The descent of the rampart offers a commanding view over the valley, while the second part of the route takes you through a real tropical forest to Roche Plate. If you decide to go down to Saint-Joseph Here is some information about the formation of the Rivière des Remparts and how the valley was settled. 290 000 years ago, a major collapse occurred in the area of the Rivière des Remparts, then the heavy rainfall began to carve out the valley, and the unstable ramparts collapsed. More than 60 000 years ago, lava flows partially filled the valley, until the Pas des Sables incident, which then isolated the area of the Rivière des Remparts once and for all from the active centre of Piton de la Fournaise. Erosion resumed and dug out the valley again. Two thousand years ago, an eruption occurred along a fissure alongside the Rivière des Remparts, producing three new craters. Commerson more than 200 m deep, Trou Fanfaron located below Commerson on the left rempart of the Rivière des Remparts, and much lower down a third cone, much less visible. The lava flows from these three craters made their way down the valley to Saint-Joseph, 22 km downstream, reaching the ocean to form Pointe de la Cayenne. Like what had happened much earlier in Bébour, these lava flows gave the valley of the Rivière des Remparts its flat, sloping bottom as we know it today. The settlement of the Rivière des Remparts happened in the same way that the cirques were settled.
    The first inhabitants of the Rivière des Remparts were “marron” slaves (runaways), followed by a few whites from the highlands, mostly from Saint Joseph. They settled in different islets including Roche Plate and Dimitile. Roche Plate was the main one and counted up to 600 inhabitants in 1965. They grew peas, beans, sweet potatoes, peaches, loquats, coffee, vetiver and maize and raised pigs, goats, poultry and oxen in the grazing areas above Roche Plate. You can still see the low walls that marked out the parcels of land. The Mahavel disaster put an end to the settlement of the Rivière des Remparts on 7 May 1965. The Journal of Reunion Island of 7 May 1965 reports the landslide that occurred at 4 o'clock in the morning 1.5 km downstream of the village of Roche Plate. ‘The prefectoral authorities took the necessary measures to evacuate the 45 families living in Roche Plate and temporarily relocate them to Plaine-des-Cafres or Saint-Joseph. In fact, most families had left their modest homes of their own accord soon after the collapse of the mountain, a phenomenon accompanied by a tremendous explosion, followed by an endless series of deafening rumblings, while huge quantities of sulphur steam spread across the valley. The inhabitants of Dimitile recall: 'It was hot ash-coloured mud, smelling of sulphur... With the barrage, we could no longer see Roche Plate'. In the night, with the fog and rain, the inhabitants of the valley believed a volcanic eruption was taking place and fled.’ The unstable rampart of Bras de Mahavel broke away and several million cubic metres of rocks and earth blocked the Rivière des Remparts. In this way, a lake was formed, which emptied gradually. The following year, the heavy rains that accompanied the passing of Cyclone Denise created another immense lake. The authorities decided to dig a channel at the foot of the western rampart to empty the lake, thus limiting the risk of flooding to Saint Joseph in the event of a rupture of the dam created by the catastrophe the previous year. Scarred by this catastrophe, which fortunately did not result in any casualties, Roche Plate remained uninhabited for 18 years. But in 1989, the ONF (National Forestry Office) undertook reconstruction work to the islet of Roche Plate and several families resettled there, including two gîtes (lodges).
    The bottom of the valley of the Rivière des Remparts is a lava flow. As with any flow, it has numerous cavities and land slips. Over time, these have been covered up and hidden by vegetation. Don’t stray from the trail, as there’s a real risk of falling several metres. Walking in the valley of the Rivière des Remparts with a qualified guide is an enriching experience that will help you understand the geological formation of the valley and the history of its settlement. Several options are possible for your return. Either climb 1340 metres up to the start of the trail, or head down the valley to Saint-Joseph on foot or by 4x4, following the 13.7 km long trail. By choosing the latter option, you’ll enter a different world: downstream of the Déblai de Mahavel, the forest disappears from the bottom of the river and you’re hiking in a grey landscape of sand and pebbles.
  • Difference in height
    1339.07 m
  • Route interest
    - The viewpoint from Nez de Bœuf - The valley atmosphere - Spend a night in Roche Plate
  • Equipment
  • Did you know ?
    At the bottom of this valley, you will find very few traces of water and yet the vegetation is king here, luxuriant, with a strong sensation of humidity. The river is underground, flowing through the numerous tunnels left by the lava. The Rivière des Remparts is the deepest valley on the island; It drives into the interior for 26 kilometres. This valley, surrounded by ramparts more than 1000 metres high, gives the impression of being far from civilisation. A night in the gîte at Roche Plate lets you feel the atmosphere of life in days gone by lived by the inhabitants of the Rivière des Remparts.
  • Documentation
    GPX / KML files allow you to export the trail of your hike to your GPS (or other navigation tool)
How to reach the start
From the north or south, take the Route des Plaines to the Maison du Volcan (museum) in Bourg Murat. The Route du Volcan begins next to the Maison du Volcan’s car park. The panels are very obvious and the Route du Volcan crosses pastures that remind you of metropolitan landscapes. Pass Nez de Boeuf, and park in the car park on the right side of the road about 2.4 km after the Nez de Boeuf viewpoint. This car park is 1 km before Piton Textor as the crow flies and faces the Commerson crater on the other side of the Rivière des Remparts.
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0 km - The start of the trail is marked by white marks at the bottom of the car park

0.15 km - You quickly reach the edge of the rampart, and the trail begins to plunge into the ramparts, heading off towards the left.

0.4 km - The path zigzags quickly downhill.

0.5 km – You reach a long straight line downhill to the left and you have already lost 200 metres of altitude.

0.9 km - The descent, which had eased off by heading to the right, continues in earnest, but the view of the Rivière des Remparts is worth taking your time to enjoy.

1.1 km - The bottom of the river is near, and the trail heads off in a long straight line to the left.

1.4 km - After a few tight turns, the descent of the rampart ends with a short straight line, then enters the undergrowth. You have lost 400 metres of altitude to reach the bottom of the Rivière des Remparts, at the place known as Mapou. Now a gently sloping descent along a path traced along the bottom of the Rivière des Remparts begins.

2.3 km - The trail approaches the right rampart, and you reach a steeper slope. The vegetation changes and becomes more sparse, giving way to the grandiose landscape of the valley of the Rivière des Remparts before you. You begin the descent on an old lava flow.

3.2 km - You approach a waterfall, and the descent on the lava flow ends with a sharp bend.

4.4 km - With the gentler slope, the vegetation gets higher, and you pass near the bottom of a ravine on your left. Be careful: the bottom is 10 metres below.

4.9 km - Pass by the Sosthène Grondin commemorative plaque, swept away by the waters here in 1987, and then the sign for the place known as 'Le Paturage - Alt 1000 m'.

5.4 km - The Davedinde waterfall on your left is dry, but the drop is deep. The slope gets steeper and you pass into a forest of filaos (coconut palms).

6.0 km - The slope is now gentle. On both sides of the path, huge chokas, pineapple flowers, low stone walls, filaos and bamboo make up the landscape.

6.1 km - You arrive at a fork where a sign indicates Bras de Caron. Continue straight on to Roche Plate.

6.9 km - You cross the Rivière des Remparts which is dry and go up the other bank. A new fork heads off left towards Bras de Caron. Continue straight on towards Roche Plate along the low stone walls.

7.2 km - A sign indicates the way to the viewpoint on Roche Plate.

7.3 km - Here is the sign indicating the beginning of the Roche Plate islet.

7.4 km - You have arrived in Roche Plate islet.
1339 meters of difference in height
  • Start altitude : 2065 m
  • End altitude : 2063 m
  • Maximum altitude : 2065 m
  • Minimum altitude : 733 m
  • Total positive elevation : 1339 m
  • Total negative elevation : -1342 m
  • Max positive elevation : 816 m
  • Min positive elevation : -789 m