Glide by private boat beneath the towering Capo Caccia cliffs to enter Neptune's Grotto — Sardinia's most spectacular sea cave, a cathedral of stalactites reflected in an underground lake. An absolute bucket-list natural wonder.
What to expect
The boat hugs the dramatic limestone cliffs of Capo Caccia before docking at the grotto entrance. Inside, a licensed guide leads you through 2.5 km of illuminated passages past massive stalactites, stalagmites, and the ethereal Lago La Marmora underground lake. The acoustics, the reflections, and the sheer geological scale are genuinely awe-inspiring. Return at your own pace with time to linger on the sun-drenched deck.
Good to know
Grotto opens at 09:00; last entry varies seasonally — confirm with the operator. The boat journey from Alghero port takes roughly 50 minutes each way, so plan a full morning. Pre-book grotto entry at grottadinettuno.it; arrange private boat directly via algherotours.com well in advance in high season.
Sail there
Luxury cruises that call at Alghero — book through us, the fare is identical and your concierge stays on your side.