Capri’s most famous attraction is the Grotta Azzurra, an unusual sea cave illuminated by an otherworldly blue light. The easiest way to visit is to take a boat tour from Marina Grande; tickets include the return boat trip, but the rowing boat into the cave and admission are paid separately. Beautiful though it is, the Grotta is extremely popular in the summer. The crowds, coupled with long waiting times and tip-hungry guides, can make the experience underwhelming for some.
The grotto had long been known to local fisherfolk when it was rediscovered by two Germans – writer August Kopisch and painter Ernst Fries – in 1826. Subsequent research revealed that Emperor Tiberius had built a quay in the cave around AD 30, complete with a nymphaeum (shrine to the water nymph). Remarkably, you can still see the carved Roman landing stage towards the rear of the cave.
Measuring 54m by 30m and rising to a height of 15m, the grotto is said to have sunk by up to 20m in prehistoric times, blocking every opening except the 1.3m-high entrance. And this is the key to the magical blue light. Sunlight enters through a small underwater aperture and is refracted through the water; this, combined with the reflection of the light off the white sandy seafloor, produces the vivid blue effect to which the cave owes its name.
The Grotta can also be accessed from land. Take a bus from Marina Grande to Anacapri and then another bus to the road's end at Grotta Azzurra. From here, a staircase leads down to a small dock where rowing boats await to take passengers into the adjacent cave.
Bear in mind that the time actually spent in the Grotta during a tour amounts to 10 minutes maximum. The singing row-boat ‘captains’ are included in the price, so don’t feel any obligation if they push for a tip.
The grotto is closed if the sea is too choppy and swimming in it is forbidden, although you can swim outside the entrance.
