Today’s journey brought us face to face with two of the Canal du Midi’s greatest engineering achievements.
Leaving Capestang, we would pass through the pioneering Malpas Tunnel before descending the spectacular staircase locks at Fonseranes and continuing into Béziers.
After yesterday’s lock-free tranquillity, the canal was about to become considerably more dramatic.
Leaving Capestang
We released the ropes and left Capestang behind, having successfully negotiated its famously low bridge without modifying either the boat or the historic stonework.
The canal continued through the vineyards of the Hérault, following a winding route towards Colombiers.
Although the Mediterranean was drawing closer, the landscape remained rural. Vines stretched beyond the towpath, while occasional glimpses of distant hills appeared between the trees.
Ahead, however, the canal seemed to disappear directly into one of them.
The Malpas Tunnel
The Malpas Tunnel carries the Canal du Midi for approximately 165 metres beneath the hill of Ensérune.
Completed in 1679, it was the first navigable canal tunnel constructed anywhere in the world.
During construction, Pierre-Paul Riquet encountered unstable sandstone. Officials ordered work to stop, fearing that the tunnel would collapse.
Riquet refused to abandon his route. His master mason secretly continued excavating, completing a trial passage in only a few days and demonstrating that the tunnel was viable.
The gamble succeeded, allowing the canal to continue beneath the hill rather than following a lengthy diversion around it.
Into the darkness
Approaching the entrance required our full attention.
The canal narrowed, the stone arch filled our view and daylight rapidly disappeared as the boat entered the tunnel.
Inside, the engine sounded louder as its noise echoed from the walls. There was limited clearance and no room for an unexpected meeting with another boat.
For a few minutes, our world consisted of stone, water and the patch of daylight ahead.
We emerged safely into the sunshine, having travelled through a structure that boats have used for nearly 350 years.
It was brief, atmospheric and unforgettable.
Just a Minute: the Malpas Tunnel
In 1679, Pierre-Paul Riquet faced one of the greatest threats to his Canal du Midi project.
His planned route encountered the hill of Ensérune, where unstable sandstone made tunnelling appear impossible. Government inspectors ordered the work to stop and proposed diverting the canal.
Riquet secretly instructed his workers to continue. Within days, they had created a trial tunnel that proved the hill could be crossed safely.
The completed Malpas Tunnel extended for approximately 165 metres and became the world’s first navigable canal tunnel.
Its name derives from the Occitan mal pas—meaning “bad passage”.
One minute—and one act of engineering defiance that changed canal history.
Towards Béziers
Beyond the tunnel, we continued towards Béziers, the city closely associated with Riquet’s life and legacy.
The canal passed Colombiers before approaching the outskirts of the city. Gradually, the rural landscape gave way to a busier and more engineered section of the waterway.
Then the view opened towards Fonseranes.
From the canal, the line of chambers descending towards Béziers presented an extraordinary sight. This was not simply another lock—it was an entire staircase built into the hillside.
The Fonseranes staircase
The Fonseranes locks were constructed as part of Riquet’s original canal and opened in 1681.
The historic structure comprises eight oval chambers and nine gates, forming a monumental staircase beside Béziers. Changes to the canal’s route mean that boats today use six chambers when travelling through the operational staircase.
The locks remain one of the most celebrated landmarks on the Canal du Midi.
They are also one of its busiest.
Boats pass through in organised groups during defined operating periods, creating a mixture of careful coordination, public spectacle and barely concealed anxiety.
Descending Fonseranes
We joined the other boats waiting to descend.
Once the gates opened, the staircase became a continuous sequence. Each chamber led directly into the next as the boats stepped progressively down the hillside.
There was little opportunity to relax.
Ropes needed constant attention, boats moved within the oval chambers and crews had to respond quickly as water levels changed. Other hire boats added further unpredictability, each with its own technique and interpretation of personal space.
Visitors watched from beside the locks, turning our boating competence—or otherwise—into public entertainment.
We concentrated on the ropes, the boat and the next opening gate.
One chamber followed another until, eventually, we emerged at the bottom.
Boat, crew and marriage had all survived.
Crossing the Orb
Beyond Fonseranes, the canal crosses the River Orb on an impressive aqueduct.
The Orb Aqueduct opened in 1858, replacing the difficult original passage in which boats had to enter and cross the unpredictable river itself.
Carrying the canal high above the Orb, the aqueduct provided memorable views towards Béziers and the cathedral of Saint-Nazaire.
After travelling beneath a hill at Malpas, we were now travelling across a river on a canal carried through the air.
The engineering ambition of the Canal du Midi seemed determined to outdo itself.
Arriving in Béziers
We continued to our mooring in Béziers and finally stopped the engine.
The day had taken us through a world-first canal tunnel, down one of Europe’s most remarkable lock staircases and across the River Orb.
Each structure solved a different challenge posed by the landscape. Together, they demonstrated the ingenuity—and extraordinary determination—behind Riquet’s canal.
Béziers was an appropriate place to finish.
Riquet was born here in 1609, and the city remains closely connected with the waterway he devoted much of his life to creating.
An unforgettable engineering day
Some cruising days are memorable because of the scenery or the places visited.
This one belonged to the canal itself.
The Malpas Tunnel demonstrated Riquet’s determination to overcome political and geological obstacles. Fonseranes revealed the scale and ambition of his original design, while the later Orb Aqueduct showed how succeeding generations continued improving the route.
Tomorrow, we would have time to explore Béziers and discover more about the city behind the engineer.
For tonight, however, we were content to celebrate completing one of the most exciting stages of our Canal du Midi journey—with our boat, nerves and marriage still largely intact.