Grottes de Hotton

The Grottes de Hotton were found in 1958 during quarrying and are geologically different from the wide chambered caves elsewhere in the Ardennes: this is a narrow fissure system cut vertically along a fault, so the visit follows walkways clinging to the sides of a deep cleft with the drop continuing below, and the Speleoclub chasm reaches a considerable depth beneath the route. An underground river runs at the bottom and is audible throughout. Formations are white and clean because the cave was sealed until its discovery, with dense stalactites, draperies and eccentric growths. The narrowness and the vertical arrangement make it feel quite unlike the show caves nearby, and it is regarded among speleologists as one of the finest in the country.

What you actually see

• A vertical fissure system - walkways down the sides of a deep cleft.
• The Speleoclub chasm - the drop continuing below the visitor route.
• Clean white formations - a cave sealed until 1958.
• An underground river - audible below the walkways throughout.

When to go

April to October; it runs reduced tours in winter and closes some months. Two hours. Tours are timed. It is cool underground and a jacket is needed. Book ahead in high summer.

Honest expectations

The route is narrow with many steps and drops, and is unsuitable for anyone uneasy with heights or confined spaces. Tours are in French unless arranged. Group sizes are limited, which means waiting. There is no wheelchair access.

Nearby

Durbuy is south along the Ourthe; Marche-en-Famenne lies west.