Bonifacio Sea Caves and Grain de Sable Rock

The boat excursions from the marina of Bonifacio, on the southern tip of Corsica in Corse-du-Sud, show the limestone cliffs on which the old town sits from the water. Departures leave from the Quai Banda del Ferro and run along the base of the white cliffs, past a detached pillar known as the Grain de Sable, which has split from the rock face, and into sea caves such as the Grotte du Sdragonato. That cave has a natural opening in its roof that lets sunlight fall onto the water from above. From the sea, the citadel appears wedged onto its cliff-top spur, with houses perched at the edge of undercut rock, which explains the town's defensive position far better than the view from land. The short circuit lasts about 30 minutes and costs roughly 12 to 15 euros per adult. A longer tour of about two hours, at around 25 to 35 euros, continues beyond Bonifacio to the Lavezzi islands, a protected marine reserve between Corsica and Sardinia. Several operators work from the quayside, with boats leaving every 30 to 60 minutes between April and October, usually from about 09:00 to 18:00. Morning departures usually have calmer seas and better light inside the caves, while the afternoon wind can make the water choppier. For photographs, the cliff-top citadel is best taken from the open deck as the boat pulls away from the harbour entrance. Crowds are heaviest in July and August, when queues form at the quay and sailings fill; outside August the short circuit rarely needs advance booking. The longer Lavezzi tours depend on the weather, so booking a day earlier is sensible if the sea is rough.