Neptune’s Grotto is an impressive deep marine cave situated on the northwestern side of the promontory of Capo Caccia, Sardinia, Italy.

This amazing cave takes its name from the Roman god of the sea, Neptune, and was discovered by local fishermen in the 18th century. Around that time, royalty began to visit the caves after reading reports sent back by explorers. Two other marvelous grottoes lie nearby: Grotta di Ricami, which is only accessible from the sea, and the Green grotto, which is not open to tourists.

Apart from being an important tourist destination welcoming visitors from all over the world, the cave is also a place of great attraction for speleologists, the only ones able to visit its most hidden recesses.

The combined length of the cave system is estimated to be around four kilometers but the public can view just 580 m.

Light infiltrates at a single point in the cave, where cave flora turns the walls green. Within this spectacular grotto, tourists can visit a 120-meter-long saltwater lake. The shallow salt lake boasts the same calcic salt structures as the rest of the cave.Guide to Grotta di Nettuno (Neptune's Grotto) at Capo Caccia, Alghero

How to reach Neptune’s Grotto in Sardinia, Italy?

You can reach this cave in 2 ways – on the water and on foot.

The water entrance to the grotto, located at the foot of the 110-meter-high Capo Caccia cliffs, is about a meter above sea level. Hence, the grotto is accessible only when the water is calm. The boat ride takes about 45 minutes and goes past the pretty Bay of Porto Conte.

Boat trips into the cave run daily in summer and are very popular, but they are less frequent during the rest of the year. It’s also worth noting that tours will not run in bad weather as disembarkation into the cave’s entrance becomes too hazardous.

The other way to enter the cave is by walking down by foot from the top of the promontory of Capo Caccia along the Escala del Cabirol (Goat’s Steps), a panoramic stairway of 656 steps.

Grotta di Nettuno opening hours and ticket price

  • November to March: 10AM to 3PM
  • May to October: 9AM to 7PM
  • April: 10AM to 6PM

The entrance ticket costs 13 €. There are reductions for children, students, and groups.


Whatever the season, the temperature remains constant, between 18 and 20°C.

Send this to a friend