Souterroscope des Ardoisières

Useful Information

Location: Route de Saint Lô, 14 240 Caumont sur Aure.
(49.091439, -0.816448)
Open: FEB to NOV Tue-Sun 11-16.
Fee: Adults EUR 10.50, Children (4-12) EUR 5.50.
Groups (20+): Adults EUR 9, Children (4-12) EUR 5.
Classification: MineSlate Mine
Light: LightIncandescent Electric Light System
Dimension: T=12 °C.
Guided tours: self guided, D=90 min. Français - French English
Photography: allowed
Accessibility: no
Address: Souterroscope des Ardoisières, Route de Saint Lô, 14 240 Caumont sur Aure, Tel: +33-231-71-15-15. E-mail:
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
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1891 slate mine closed.
01-MAY-1994 museum opened to the public.



Souterroscope des Ardoisières (Souterroscope of the slate quarries) is an underground museum inside an abandoned slate quarry. The slate was discovered in the 19th century during works near the church. At the beginning, the extraction was completely illegal, at the foot of the church of Caumont l'Éventé. Nevertheless, the slate mine later was the only one in Normandy which reached industrial dimensions. Due to the high quality it was called the blue gold of Caumont and was mined for house roofs and road maintenance.

The mining went on until 1891, but it was interrupted several times. Like all things, the price of the slate went up and down, and there were times when the slate mining became unprofitable. Finally, the lack of a railway line which would have provided a means of transport in combination with a crisis in the construction industry caused the closure.

The mine was abandoned for more than a century, when it was converted into a museum in 1994. The development of a mine into a show mine is not special, but normally it is not called an underground museum. The main difference is actually, that show mines are guided and museums are self-guided. In general, it is quite dangerous to walk around in a mine, which is the reason why they are visited on guided tours. On the other hand, a museum allows its visitor to stop at any interesting exhibit for as long as they want. The visit here is actually a sort of tour, the films are shown in a loop, and so the tour re-starts every 12 minutes. There are tours in French and English.

The underground museum has four chambers. In the first, a video on the water cycle is shown. There is an underground lake which is the groundwater table. The second has a sort of art installation, a fountain illuminated with coloured light called Arc en Terre chasm. In the third, another video shows the extraction of slate. The fourth shows how the mined slate is cut into the necessary forms for roofing and other uses. There is also a mineral exhibition, with emphasis on semi-precious stones. This exhibition obviously has no connection to the slate.

The site is