-What you can expect- It may be named after the Roman god of the sea – but Neptune's Grotto was discovered only a couple of hundred years ago. Hidden just above the water level at the base of the towering and remote Capo Caccia cliffs, the grotto is one of Sardinia's most dramatic natural attractions.After sailing from the harbour, you'll pass rugged coastline before reaching the grotto in under an hour. On arrival, you can choose whether to go in to Neptune's Grotto or not. If you do, you'll see stalactites biting down like incisors from the roof of the cave and stalagmites stabbing up from the floor like daggers, and a saltwater lake that stretches out for 120 metres – all while having the geology expertly brought to life by your local guide.If you choose not to take the subterranean tour, you can stay on board basking in the sunshine. Either option is a great way to spend some time before a leisurely trip back to port.