At the foot of the promontory, just below the Church of San Pietro, a sea cave opens into the black rock at water level. The cave is named after Lord Byron, who stayed in Portovenere in 1822 and reportedly swam across the Gulf of La Spezia from this point to visit Percy Shelley, who was living at San Terenzo on the eastern shore — a distance of about eight kilometres. The cave itself is accessible only by boat or by scrambling over the rocks at low tide.
The story fits the mythology of the Gulf of Poets (Golfo dei Poeti), as the locals call it: Byron, Shelley, and later D.H. Lawrence and Virginia Woolf all spent time on these shores. Whether Byron genuinely swam from here is disputed — some accounts place his departure point elsewhere — but the plaque on the rock above the cave insists he did, and the image is too good to let historical pedantry spoil it.
story: "Shelley drowned in this same gulf just weeks after Byron's supposed swim, when his schooner Don Juan foundered in a summer squall in July 1822. He was 29. His body washed up near Viareggio and was burned on the beach in a ceremony attended by Byron and Leigh Hunt."