Neptune's Grotto
One of Sardinia's great natural wonders - a vast sea cave beneath the cliffs of Capo Caccia, filled with stalactites, stalagmites and the remarkable underground Lake Lamarmora.
A hidden world beneath Capo Caccia
Neptune's Grotto - Grotta di Nettuno - opens at sea level beneath the dramatic limestone cliffs of Capo Caccia, around 25 km from Alghero.
Inside, the visitor route passes huge calcite formations, cavernous halls and the clear waters of Lake Lamarmora, one of the largest salt-water lakes found inside a cave in Europe.
The experience is memorable whichever way you arrive: descend the cliffside Escala del Cabirol on foot, or sail across the bay from Alghero and enter directly from the sea.
Access by both land and sea depends on weather and sea conditions. Strong winds or rough seas can force the grotto to close at short notice.
Two ways to reach Neptune's Grotto
The entrance can be reached either overland via Capo Caccia or directly from the sea by boat.
By land - Escala del Cabirol
Drive, take the bus or travel to Capo Caccia, then descend the famous cliffside staircase to the grotto entrance.
- Approximately 660 steps each way
- Land visits require advance reservation
- The reservation itself is not the admission ticket
- Arrive at the top of the staircase around 40 minutes before your tour
- Wear sensible footwear and bring water in hot weather
By sea - boat from Alghero
Boat services operate from Alghero harbour and approach the entrance beneath the cliffs of Capo Caccia.
- No separate land-entry reservation is needed
- Boat passengers are allocated a grotto visit place
- The boat fare does not include grotto admission
- Services are operated by private boat companies
- Sailings depend heavily on sea conditions
Bus from Alghero to Capo Caccia
ARST runs a daily extra-urban service from the main terminal in Via Catalogna, Alghero. The journey to Capo Caccia takes around 50 minutes.
Opening times
Open daily except 25 December. Hours and access can change, so confirm on the official website before travelling.
Admission prices
Reduced admission includes visitors aged 6-17 and certain other eligible groups. Additional concessions and free admission apply in specific circumstances.
What you'll see
The visitor route passes through a sequence of remarkable cave chambers shaped over thousands of years.
Lake Lamarmora
The extraordinary salt-water lake that greets visitors near the cave entrance.
The Reggia
A spectacular chamber of towering columns, calcite flows and dramatic formations.
The Christmas Tree
One of the grotto's most distinctive stalagmite formations.
Smith's Hall
Home to the Great Organ, the largest column in the visitor section of the cave.
Lacework Hall
Delicate columns and formations create some of the cave's most intricate scenery.
Music Gallery
A natural balcony giving elevated views across the Reggia and Lake Lamarmora.
Practical visitor advice
Wear good footwear
Cave floors can be damp and the land route involves a long staircase.
It's cooler underground
Even on a hot Sardinian day, the cave feels cool and humid compared with the cliffs outside.
Think about the return climb
The Escala del Cabirol is beautiful, but remember that you need to climb back up after the visit.
Erreichbarkeit
The land route is unsuitable for visitors who cannot manage a very large number of steps. Contact the grotto directly for current accessibility advice.
Photography
Follow staff instructions inside the grotto and avoid blocking the guided visitor route.
Don't cut it fine
For a land visit, the official advice is to reach the top of the staircase around 40 minutes before your tour.
Book and check the latest information
Land access requires a reservation. Admission can also be purchased online or at official ticket offices in Alghero and Capo Caccia.