Wallonia · about 5 km from Rochefort
Lesse souterraine (Grotte de Han)
Closed to divers
No public diving access: the sumps were explored by Belgian cave divers.
- Max depth45 m
- CertificationFull cave
- SpecialExperienced divers
Diving and fills
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Fills nearby
- Fill stationNérée Diving (Namur)Air, nitrox, O₂, trimix (200 and 300 bar)Route ↗
- Fill stationCarrière de Villers-Deux-Églises (V2E)Air and nitrox (200, 230 and 300 bar)Route ↗
- Fill stationDive Factory (Braine-l'Alleud)Air, nitrox, trimix, O₂, helium; 200 and 300 barRoute ↗
Now at Lesse souterraine (Grotte de Han)
The dive
According to Delaby this is the longest flooded system in Belgium (as of 1988). Per an 18th-century observation by Lambert de Saumery, the river took 24 hours to cross the hill underground.
1 earlier accident or incident has been reported at this cave. Read what happened ↓
Profile and sections
According to Delaby this is the longest flooded system in Belgium (as of 1988). Per an 18th-century observation by Lambert de Saumery, the river took 24 hours to cross the hill underground.
- Depth and profile
- 11 sumps, 842 m flooded in total (as of 1988); S4 255 m / -32 · junction sump 180 m / -45
- Configuration
- No data on passage size; expect dry sections between the sumps.
- DPV: unknown
- No data on scooter use or passage size.
Who can dive where
- At least Full cave
- Configurations: Backmount / twinset / Sidemount / CCR / Small cylinders / no-mount (speleo sumps)
- Configuration unknown — research beforehand
- Goes down to 45 m (trimix or deco may be needed)
- Experienced divers only
This is how the planner decides who in your team may dive this cave. Rules your own trip adds (organizer, a mail, the AI) show with your trip.
How to get there
The underground course of the Lesse between the Gouffre de Belvaux (where the river disappears) and the Grotte de Han (where it resurfaces, now a show cave). The sumps were explored by Belgian cave divers; there is no public diving access.
Around Lesse souterraine (Grotte de Han)
Fills3 fill stations · nearest 45 km
Nérée Diving (Namur)
Rue Père Cambier 17, 5000 Salzinnes (Namur)
Air, nitrox, O₂, trimix (200 and 300 bar)
Mon 11:00–19:00, closed Tue, Wed–Fri 11:00–19:00, Sat 11:00–18:00; Sun: ask
Dive shop with its own club: weekly quarry dives and pool training, tec diving courses (OC and rebreather: rEvo, Horizon). Walk-in fills for visitors: ask.
Carrière de Villers-Deux-Églises (V2E)
Rue des Traigneaux 104A, 5630 Cerfontaine
Air and nitrox (200, 230 and 300 bar)
Book via carrierev2e.be; hours and rates on the operator's site
Open (non-overhead) dive quarry, to ~28 m, with changing rooms and a café. Lines and cenote-style decor are laid out underwater to simulate cave dives without an overhead: good for introduction and practice (following the line blind, jumps) before a cave course.
Dive Factory (Braine-l'Alleud)
Chaussée de Tubize 475, 1420 Braine-l'Alleud
Air, nitrox, trimix, O₂, helium; 200 and 300 bar
Ask
Dive shop with gas blending. Second shop in Wezembeek-Oppem (+32 2 353 08 98). CCR supplies (sofnolime): ask.
News
All (1)
Accidents and incidents
What happened at this cave before, with the sources. No names are given; read it as a lesson for your own planning.
- In 1968 a diver disappeared while exploring the Gouffre de Belvaux.
Access and rules change: check what applies locally right before your trip. Source: GDELT Project and the news feeds of diving magazines. Search for more news ↗ Searched automatically, last on 13 Nov 2026.
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