Grottes de Nichet

Useful Information

Location: Fromelennes, Ardennes
(50.120640, 4.864160)
Open: APR to MAY daily 14-18.
JUN to AUG daily 10-19.
SEP daily 14-18.
Last tour 1 h before closing.
Fee: Adults EUR 6, Children (7-16) EUR 3.50, Children (0-6) free.
Groups (15+): Adults EUR 4, Children (7-16) EUR 3.
Classification: SpeleologyKarst cave
Light: LightIncandescent Electric Light System
Dimension: VR=53 m, T=9 °C.
Guided tours: D=60 min, VR=30 m. Français - French English Nederlands - Dutch
V=4,800/a [2008]
Accessibility: no
Bibliography: Albert Meyrac (1900): Géographie illustrée des Ardennes Nabu Press, ISBN-10: 1174552832, ISBN-13: 978-1174552830
Address: Grottes de Nichet, Rue des Ecoles, 08600 Fromelennes, Tel: +33-324-420014, Fax: +33-324-423756. E-mail: contact
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.


16th century cave first mentioned.
1895 opened to the public.
1950 Grotte du Trasson discovered.
1953 Grotte du Trasson explored.
1950s cave closed.
1965 excavations at the cave revealed the human presence.
11-APR-1987 cave renovated, electric light installed, cave reopened.


The Grottes de Nichet (Caves of Nichet) actually does not deserve the plural, there is only one cave. This is a very old show cave, opened to the public in 1895, according to Albert Meyrac: Géographie illustrée des Ardennes. At this time each chamber was called a grotte, and a cave with more than one chamber was called Grottes.

This cave is located in the Givetian limestones of the Ardennes, actually from the geologic view it is a Belgian cave. However, there is a corridor of France protruding from the region Champagne, surrounded by Belgium, with this cave at the tip. This makes this cave quite unique, it is the only show cave in the northeast of France.

The cave has three levels, which follow the highly inclined banks of the limestone. The upper two levels are developed for the public. The cave requires climbing 114 steps, as the tour descends some 30 m. The highlight of the tour is the salle de la Roche, where a sound system recites a part of Jules Verne's Journey to the Center of the Earth.

The salle du Squelette (chamber of the skeleton) was named after a thief who planned to use the cave as a hideout in 1772. He only had a candle for light, and after it went out, he could not find the exit any more. As a result he died in the cave and his skeleton lies here. So goes the legend, but the skeleton is actually a dripstone formation. But some say there actually was a skeleton, which was found during the first development in 1895.

The cave was known to the villagers under the reign of Louis XIV, but no one dared to venture inside, because it was believed that the cave was the entrance to hell. From the 19th century the cave was actually visited and explored. When the cave was first developed in 1895, the works revealed bones in the sediment, which was subsequently excavated. The remains of cave bears, mammoths, reindeer, and humans were found. Excavations in 1965 around the cave revealed human presence. The last excavation in 1995 revealed a grave from the Bronze Age containing the skeletons of 17 people.

Nearby is a second cave, the Grotte du Trasson or Trou du Trasson. It was discovered in 1950 by the dog of the guide Monsieur Barbier. So it was named Trasson, because the dog was a terrier named Trasson. At first the entrance was too narrow for a man, only the dog could enter, but the entrance was widened in 1953 and the cave explored. The cave may be visited by speleologists.

Not only the cave was renovated during the last renovation in 1987. The surface was also updated, with a new parking lot, an entrance building with ticket office and chale, beergarden, and barbecue area. There is also a playground for children and one for adults called fitness trail. Much younger is the black pine observatory, an outlook tower with two platforms, one at 8 m and one at 12 m, accessible by a Nepalese footbridge. Definitely a nice place to spend an hour with a cold beer or a cup of coffee and homemade pastries, after the strenuous cave tour.


The most marvellous geological curiosity in the Ardennes is undoubtedly the Grotte de Nichet, carved out of the Givet limestone which, about 3 kilometres long, crosses French territory at the northern tip of the department and continues into Belgium for a length of at least twelve leagues.

These limestone banks, which run almost parallel to the railway line for a length of 300 metres, form an angle of 110 degrees with the compass needle, whereas in the Charlemont tunnel, the banks form an angle of 25 degrees with the compass needle and are almost perpendicular to the railway line A similar layout of the limestone banks, but in the opposite direction, is found to the south of the village of Fromelennes, and the banks appear to meet at the Nichet cave. From the top of the hill, where the entrance to the cave is located, you can see the limestone banks coming from the direction of Flohimont and Rancennes plunging southwards, while those coming from Fromelennes, which are clearly visible at the place known as La Cote, opposite the Donau marble sawmill, plunge eastwards at a much shallower angle.

It therefore seems likely to us that the Nichet cave originated in a void that formed as a result of a difference in the inclination of the banks where they meet after they were broken and uplifted. In this void, a series of boulders crumbled together, taking up different positions and intertwining, thus subdividing the space between the banks into chambers, galleries and corridors, whose walls were covered by limestone deposits carried along by rainwater, which at the time must have fallen in abundance at fairly high temperatures, easily dissolving the limestone near the outer surface. The surface area occupied by the galleries, which are now merged, is 100 metres long and 70 metres wide. They are no more than 25 metres deep, but as no water has been deposited in the lowest parts of the cave, we can only conclude that the water from the seepage is flowing through galleries that have not yet been identified and which are at great depth. As the rainwater penetrates through the interstices, it becomes loaded with limestone. It then falls, drop by drop, onto the fallen blocks, forming stalagmites or welding the blocks together, causing some of them to lose their original shape. (See Watrin in the Bulletin de la Sociéré d'Histoire naturelle des Ardennes: La Grotte de Nichet).

Until 1894, the cave was virtually abandoned. However, as the entrance remained free, a few visitors, candles or torches in hand, ventured into the more remote galleries and, in order to find their way easily, they tied the end of a rope near the entrance, which they unwound as they progressed through the galleries. The visit was quite arduous. The paths, which were almost impassable, were made very slippery by the limestone-laden water, which fell drop by drop from the galleries, forming stalactites and stalagmites in some places, some of which eventually came together. You passed over steeply sloping blocks where there was nothing to hold you back. The foxes took refuge in some of the galleries where, as proof of their habitual stay, they left their bones. The bats were grouped together in the first room. When the cave was officially opened, they were found stuck to the ceiling.

Albert Meyrac (1900): Géographie illustrée des Ardennes