Conference: Bestouan Port-Miou – The Mysterious Rivers
Presentation
On Tuesday, February 10, 2026, at 6:30 PM, the Cassis Cultural Center invites you to a conference at the Oustau Calendal Convention Center:
BESTOUAN – PORT-MIOU – The Mysterious Rivers
Well known among cave-diving hydrogeologists but little known to the general public, the underground river of Port-Miou is a fascinating reservoir of fresh water. Despite numerous diving expeditions, no one has yet reached the end of its long and mysterious story.
Mysterious, its exact source remains unknown. Furious, it can reach a flow of 150 m³ per second during floods. Playful, it weaves its way through limestone rock and plunges to depths of up to 230 meters — eluding even the most experienced divers.
The underground river of Port-Miou remains an unsolved puzzle, though it is the subject of extensive research.
Located between the calanques of Port-Miou and Port-Pin, its source may lie somewhere between the southern slopes of the Sainte-Baume range and the Cuges plain.
According to some writings, the Romans were already drawing water from it. Indeed, this river is a remarkable fresh water reservoir that divers have been trying to trace upstream for years.
Indoor event at the Oustau Calendal Convention Center
6:00 PM: Doors open
6:30 PM: Conference begins
Rate: €10 per person – €5 for CCC members
Unnumbered seating (open seating)
BESTOUAN – PORT-MIOU – The Mysterious Rivers
Well known among cave-diving hydrogeologists but little known to the general public, the underground river of Port-Miou is a fascinating reservoir of fresh water. Despite numerous diving expeditions, no one has yet reached the end of its long and mysterious story.
Mysterious, its exact source remains unknown. Furious, it can reach a flow of 150 m³ per second during floods. Playful, it weaves its way through limestone rock and plunges to depths of up to 230 meters — eluding even the most experienced divers.
The underground river of Port-Miou remains an unsolved puzzle, though it is the subject of extensive research.
Located between the calanques of Port-Miou and Port-Pin, its source may lie somewhere between the southern slopes of the Sainte-Baume range and the Cuges plain.
According to some writings, the Romans were already drawing water from it. Indeed, this river is a remarkable fresh water reservoir that divers have been trying to trace upstream for years.
Indoor event at the Oustau Calendal Convention Center
6:00 PM: Doors open
6:30 PM: Conference begins
Rate: €10 per person – €5 for CCC members
Unnumbered seating (open seating)
General informations
- Duration :
- Between 1 hour and 2 hours
- Type of events :
- Conferences
- Recommended :
- for all ages
Destination
20 avenue Emmanuel Agostini
Centre Culturel Cassis
13260
CASSIS
GPS coordinates
Latitude : 43.21647
Longitude : 5.53846