Blue Grotto

In Roman times the cave served as a maritime nymphaeum, a submerged annexe to the Augustan and Tiberian villa at Gradola, which survives only as a few ruins. Roman statues of Poseidon, of a triton and of other creatures of the sea are taken to have been ranged along its walls, and resting places were made around the edge of the water; by one account it was also the private bathing place of the emperor Tiberius, who left Rome for Capri in AD 27. In the south-western corner the Romans built out a platform to the water's edge, levelling it with crushed brick.

Beside that platform three branches of gallery run back into the rock, the Galleria dei Pilastri, leading to the chamber later called the Sala dei Nomi and beyond it to the Sala della Corrosione, where the part that can be entered ends. The unbreathable tunnels beyond appear not to reach the open air at all, and are thought to be a fruitless Roman search for fresh water. The passages into the cliff were long taken for ancient stairways up to the palace of Tiberius; they are natural, and narrow and end in the rock.

After the fall of the Roman empire the grotto went into a long decline. It was never entirely forgotten: the name Gradola, from the landing place nearby, is already on a chart in Vincenzo Coronelli's Isolario of 1696, and through the eighteenth century the islanders knew the cave by that name. Even so, no one would go inside. Old Capri legends held it to be occupied by spirits and devils, and sailors and islanders alike kept clear of what was called the cursed cave. The story told on the island was of two priests who set out to drive the devils from it, swam in, and came out a few minutes later in panic as though they had seen the face of the devil; from that moment, it was said, both of them raved.

On 17 August 1826 the Prussian poet August Kopisch, the German painter Ernst Fries, the Capri sailor Angelo Ferraro, the innkeeper Pagano, who had pressed them to the attempt, and the donkey-driver Michele Federico set out to explore the opening on the north-western side of the island, in defiance of the legends. Kopisch also settled its name, calling it the Blue Grotto; neither grotta Pagano nor grotta Glauca, put forward by the Russian exile Apostol Mouravieff, caught on. He published his account of the day in 1838 in the yearbook Italia, under the title The Discovery of the Blue Grotto. He did much to spread the cave's fame, and has even been called its discoverer.

The cave was known beyond Capri before Kopisch wrote. A Neapolitan song of the eighteenth century, La grotta azzurra, names it, which is taken to show that it was familiar well before 1826, and the romantic writers had put it into print, Wilhelm Waiblinger in his Legend in the Blue Grotto of 1828 and, with far greater effect across Europe, Hans Christian Andersen in The Improvisatore of 1835. The rediscovery redrew the Italian stages of the Grand Tour and brought wealthy European travellers to an island that Daniello Bartoli had called a rock of the desperate. August Bournonville set the second act of his ballet Napoli in the grotto in 1842, giving it a ruling demon, Golfo, who turns the heroine Teresina into a naiad. Mark Twain visited in 1867 and set down his thoughts in The Innocents Abroad. Between 1875 and 1877 Ludwig II of Bavaria had a Venus Grotto built in the park at Linderhof whose scene could be changed into the Blue Grotto of Capri, an effect got with arc lamps and a plant of electric generators. The cave features in Ann Weil's Red Sails to Capri of 1953 and returns in Alberto Moravia's Il disprezzo of 1954.

It was the archaeologist Amedeo Maiuri, engaged on several archaeological investigations at Capri in the twentieth century, who recognised the cave for a maritime nymphaeum. Three Roman statues were lifted from its floor in the 1960s and are kept in the Museo della Casa Rossa at Anacapri. Pliny the Elder had described the cave as peopled by a Triton playing on a shell, and since the recovered Triton has lost the arms that would have held the conch, the figures are taken to be the ones he saw in the first century AD. Seven statue bases were brought up from the floor in 2009, which implies at least four more figures still lying on the bottom. Working with the archaeological superintendence of Pompeii, the Marevivo association intends to place statues in the grotto to show the arrangement it may once have had, a crowd of tritons led by a Neptune.

The Sala dei Nomi carries the signatures left on its walls by visitors of the nineteenth and twentieth centuries. The mouth is roughly a metre high at low tide, so it can be passed only on a low and quiet sea, and visitors lie flat in a four-person rowing boat while the boatman hauls it through on an iron chain set into the entrance. In 2011 a visitor's neck was broken as he was taken in, an injury that changed his life; the Cooperativa Battellieri Grotta Azzurra denied liability at first but settled the claim for damages, and it was concluded that the boatmen had gone on entering when the sea was too dangerous for it. Swimming in the grotto is forbidden. The cave is protected as Italian national heritage and is administered as a state museum and archaeological park of the Ministry of Culture, in the commune of Anacapri.