| Isthme | |
| Address: | 56510 Saint-Pierre-Quiberon |
| Borough: | Morbihan |
| Country: | France |
| Coordinates: | 47.5469°N -3.1336°W |
| Line: | Auray–Quiberon railway |
| Platform: | 1 |
| Tracks: | 1 |
Isthme (French: Halte de L'Isthme) is a railway halt in Saint-Pierre-Quiberon, Morbihan department of Brittany, France.[1] The halt is situated within close proximity of the Fort of Penthièvre. It is located at kilometric point (KP) 605.000 on the Auray–Quiberon railway. The halt is served seasonally during summer months only by TER Bretagne services operated by the SNCF, between Auray and Quiberon.[2]