The Canal de Nantes à Brest, completed in 1842, crosses inland Brittany from east to west over about 330 km, largely via canalised rivers (the Erdre, the Isac, the Oust, the Blavet, then the Aulne). The towpath running almost its entire length makes it one of the longest fully traffic-free bike crossings in France — and one of the easiest, given the near-total lack of elevation gain.
A route built to dodge a naval blockade
Unlike La Vélodyssée, which follows the Atlantic coast, the Canal de Nantes à Brest cuts straight across inland Brittany. The route was decided under the First French Empire to provide a secure inland link between Nantes and Brest, the Atlantic’s two major military ports, at a time when the British Royal Navy made coastal sailing risky. The canal has since lost all military or commercial use, but its towpath, locks and lock-keeper’s houses still bear witness to that history.
Between Nantes and Carhaix-Plouguer, the route is exactly the same as La Vélodyssée, which follows the same towpath over this stretch (see La Vélodyssée’s Nantes-Redon, Redon-Pontivy and Carhaix-Pontivy stages for details on this shared section). The two routes split at Carhaix: La Vélodyssée heads north to reach the Channel at Roscoff, while the Canal de Nantes à Brest continues west, along the canalised Aulne, to the Brest roadstead.
No need to do it all at once
As with any route of this kind, the full crossing naturally breaks down into stretches of a few days. The short, heritage-rich Josselin-Pontivy stretch (Josselin’s château, Pontivy’s Napoleonic architecture) makes a good weekend introduction. The final Carhaix-Châteaulin-Brest section, less well known and noticeably quieter than the stretch shared with La Vélodyssée, will appeal to cyclists seeking a bit more solitude.
How to approach the ride
The towpath, generally flat and away from traffic, suits a wide range of riders, from families with kids to more experienced cyclotourists looking for a relaxing route. The locks, regularly spaced, naturally punctuate the ride and make for good rest stops.
Think about luggage logistics if riding several stages in a row: several rental shops along the canal offer panniers and sometimes stage-to-stage luggage transport.
When to go
The ideal window runs from April to October. Brittany’s oceanic climate stays changeable year-round: it’s worth packing rain protection whatever season you choose.
Good to know
The canal passes through several towns well served by train (Nantes, Redon, Pontivy), making it easy to join or leave the route at different points without heading back to the start — useful flexibility for a route of this length.
