grotte des Hirondelles

Grotte des Hirondelles is a small sea cave on the Pointe du Décollé in Saint-Lunaire, on the Emerald Coast between Dinard and Saint-Malo. Together with the neighboring Grotte des Sirènes, it forms a pair of caves carved by the waves into a rocky headland that juts far out into the sea — a spot that has drawn walkers for decades looking for a different kind of coastal scenery than the region's beaches.

Where exactly is the cave?

The entrance to the Grotte des Hirondelles sits at the foot of the northwestern end of the Pointe du Décollé, cut into granite that dates back more than half a billion years to the Neoproterozoic. The entrance porch itself is 5 to 6 meters high today, and the passage runs roughly 24 meters into the rock. That's modest next to a large karst cave system, but enough to feel dramatic when waves are breaking right at the opening.

How do you get there?

The Pointe du Décollé is within walking distance of the center of Saint-Lunaire, right along the coastal path linking the town to Saint-Malo and Dinard. The headland is riddled with cracks and cave entrances, and visiting them realistically only works at low tide, when the water retreats enough to expose the base of the rocks and the way into the caves. At high tide, waves cover most of the lower part of the point, so it's worth checking local tide tables before setting out along the cliffs.

What else is there to see besides the cave?

The Pointe du Décollé is above all a viewpoint — one of the best along this stretch of coast. From its top, the panorama stretches from the Pointe de la Varde to the Cap Fréhel, taking in Longchamp beach to the west and the Grande Plage with its Grand Hôtel to the east. On the northeastern tip of the headland stands a boundary cross dating from 1880, and among the rocks you can spot the remains of World War II bunkers, a reminder that this coastline was part of the German Atlantic Wall defenses. There's also a former tunnel that once connected the old Saint-Lunaire church to the headland — long since collapsed and inaccessible, but still mentioned in local accounts of the site.

A bit of the cave's history

The Grotte des Hirondelles didn't always look the way it does now. In the early 20th century its entrance was picturesque enough to feature on postcards sold to visitors touring the Saint-Malo and Dinard area. Since then, part of the vault has collapsed, changing the cave's appearance — it's now less accessible and less striking than in the era when it was being photographed for postcards. The cave was formally surveyed on September 22, 1990, when speleologists Jean-François Plissier and Jean-Yves Bigot documented its dimensions and layout.

When is the best time to visit?

The best time to come is at low tide on a calm day, when the rocks are dry and safe to walk over and the cave's interior can be reached without getting your feet wet. In summer, early morning or late afternoon also give the best light for photographing both the cave and the wide panorama from the point. Outside the high season, the site is often nearly empty, which for many visitors is part of the appeal — a wild stretch of coast without the crowds.

Frequently asked questions

Can you visit the cave at any time of day? No — access depends on the tide. At high tide much of the base of the rocks is submerged, so visiting really only makes sense at low tide.

Is there another cave nearby? Yes, right next to it is the Grotte des Sirènes — together they form the well-known pair of caves on the Pointe du Décollé.

Is the cave large? No, it's a small sea cave about 24 meters long with an entrance 5 to 6 meters high, cut into granite rock.

What else is worth seeing on the headland? A viewpoint with panoramic views from the Pointe de la Varde to the Cap Fréhel, an 1880 boundary cross, and the remains of World War II bunkers.