Neptune's Grotto, the Grotta di Nettuno, is one of the largest marine caves in the Mediterranean and the signature sight of the Alghero coast. It lies at the foot of the Capo Caccia headland, about twenty-five kilometres from town, where cliffs drop sheer into the sea. Inside, a chain of chambers is decorated with stalactites and stalagmites, a salt lake fills the lower level and the walkways run just above the water. The cave is entered at sea level, and guided tours lead visitors through the chambers in around half an hour. There are two ways to reach it. Most visitors descend the Escala del Cabirol, a long cliffside staircase with sea views carved into the rock, while in the warm months boats also run from Alghero harbour. The route you choose changes the mood of the visit, and both depend on the weather.
What you see
The cave mouth opens just above the waterline, and the tour passes through galleries lit to bring out the limestone formations, including stalactites, stalagmites and a pool of clear water. The size of the main chamber is impressive, and the air is cool and humid even on warm days. The walkways are damp, so shoes with grip are best. The grotto is a natural monument, and guides explain the geology and the legends behind the name.
Practicalities
The venue publishes its opening times and sets them by season. It is open daily from morning to mid-afternoon, with guided tours starting on the hour and last entry at 3 pm, and from mid-November to mid-March it is closed on Thursdays. It is also closed on 24 and 25 December.
The cave opens only when the sea is calm enough, so closures can come at short notice, and it is wise to check the day before. Boat departures from Alghero are generally a warm-season service, so in winter plan to arrive by road and take the stairs.
Making the most of it
Drive or take a taxi out to Capo Caccia, descend the staircase for views, and allow time to climb back up, which takes effort. A visit pairs naturally with a morning in Alghero old town. Go early in the day for better light on the cliffs and fewer visitors, and carry a layer for the cooler air inside.
What to expect
The experience
A guided walk of about half an hour through the chambers and walkways of a sea cave, reached by a cliff staircase or, in warm months, by boat.
Best time
A calm, clear day, early in the morning. Winter works if the sea is calm, but the cave closes in rough weather.
How long
About half an hour inside, and two to three hours with the trip from Alghero and the stairs.
Tips
Check the venue's opening page the day before, wear shoes with grip and bring a layer, since it is cool and damp inside.
Quick picks
- Best for
- Anyone who wants a dramatic natural sight within reach of Alghero.
- Families
- Children who can manage the long staircase enjoy it, and the tour is short enough to hold attention.
- Couples
- A morning at the cliffs followed by lunch in Alghero old town.
- Pair with
- Alghero old town, a winery visit or the Nuraghe Palmavera.
- Time needed
- Half a day from Alghero.
Good questions
Is Neptune's Grotto open in winter?+
Yes, it is open daily in autumn, but from mid-November to mid-March it is closed on Thursdays. It also closes whenever sea conditions are unsafe.
How do I reach the cave?+
By road to Capo Caccia and then down the Escala del Cabirol staircase, which has about six hundred steps. In the warm months boats also run from Alghero harbour.
How long is the tour?+
Guided tours start every hour and last roughly thirty minutes. Allow more time for the staircase and the views.
Is it suitable for young children?+
Yes, if they can handle the stairs and the damp walkways. Carry toddlers carefully because the steps are many and exposed.
What should I wear?+
Shoes with grip and a light layer, since the cave is cool and damp. A windproof jacket is useful on the cliffs.
