Blue Grotto, Capri

The hidden sea cave in Italy’s quiet Capri is a mesmerising sight. Its source of wonder comes from its gleaming blue waters, transforming the dark cave into an enchanting phenomenon.

Its splendour has been known throughout history, with ancient beings marvelling at the natural light much the same as we do today.

The History of Blue Grotto

This cave hasn’t just been a new discovery, for it has a long history with humans. First seen documented in 27 A.D. when Tiberius, Emperor of the Roman Empire at the time, moved to Capri. Here he lived a lavish lifestyle in his Villa Jovis, a palace which sat atop a thousand-foot drop to the sea. The jaw-dropping cliff was not merely for show, for the Emperor was known to toss traitors or enemies over the cliff. The Blue Grotto, named Grotta di Gradola at the time, was Emperor Tiberius’ private swimming pool. He decorated the cave as a marine temple dedicated to sea nymphs. With a number of statues lining the cave as well as resting areas along the cave’s edges. Some of these statues of sea-gods were recovered from the bottom of the cave and now reside in the museum in Anacapri. After the Emperor’s death, the cave was soon abandoned, remaining hidden for centuries. Legends of spirits and demons living in the cave grew over the years, with the local fisherman fearing it. However, on April 18, 1826, the cave was “rediscovered” by a German writer and painter, named August Kopisch and Ernst Fries. The two were taken into the cave by a local fisherman named Angelo Ferraro.

Why is it Blue?

The mysterious blue glow of the water comes from the sunlight in the sky. However, instead of the light coming from above, it shines through a hole at the bottom of the cave. The hole is around 9 metres wide and is located directly below the entrance to the Grotto. The hole filters the sunlight and combines with the entrance light to illuminate the waters from below. As light travels through the water, colour wavelengths are absorbed by the water with red being the first to go and blue being the last. So, as the light travels through the water to the underwater entrance, it has already lost most of its colour spectrum and only blue remains. When the light then reflects up into the cave it casts an incredible blue glow that has been amplified due to the journey of the light. This captivating glow illuminates whenever the sun is shining, so viewing the cave during the middle of the day when the sun is brightest is advised.

What is it like inside the cave?

Firstly, entering the cave is almost as much of an experience as being inside! Due to the incredibly narrow entrance, the boatmen are forced to bring their oars into the boat and guide their vessel into the cave using only a guideline which they pull themselves along. Once inside the cave, you may be surprised by its size. It is 25 metres wide and 60 metres long and the blue water below descends to 150 metres. The blue light that shines through the water illuminates the roof of the cave and it is mystical to behold. A bonus of your experience is that the skippers sing. The cave walls echo with the Neapolitan folk songs sung by your guide and this simply adds to the magical experience of the Blue Grotto.

Can you swim in the Blue Grotto?

Sadly, swimming is not allowed in the Blue Grotto, but this is for safety reasons. Due to the low, narrow entrance to the cave, if the weather became rough then injury would be highly likely if you were to hit the rocks. Some people do attempt to swim once the tourist boats have gone but this is illegal and not at all advised.

If you would like to swim in one of Capri’s caves, then there are other spots along the coastline where you can do this. On the southern side of the island lies the Grotta Verde (Green Grotto) where you can jump from your boat and swim. The water here is named because of its colour but it is, in reality, more blue than green. The Green Grotto is not as enclosed as the Blue Grotto, but it does have a rocky arch that you can swim through. The water here is crystal-clear and far shallower so you can drift close to the rocks and see them both above and below the water. When swimming through the cave, be sure to cast your eyes upwards to see the blue reflection on the grotto roof.

How to see the Blue Grotto Today?

Nowadays, hundreds of people visit this mesmerising wonder, with the only way to visit by rowboat. Either hop on an organised boat tour or hire a boat and skipper for the day. The best time to see the glow is around 2 pm, but as it is the most picturesque, it is, of course, the busiest time. When you arrive at the cave you will see a bustling commotion of boats, all waiting their turn to float through the narrow entrance. Each boat going into the cave can only hold around four people and boats must enter one at a time, which can lead to a lengthy wait for some visitors. Though the wait could be a while, the anticipation is palpable, and you can take this opportunity to sit back and enjoy a view of Capri whilst bobbing on the water. And when you finally get into the cave, you’ll know that the wait was well worth it.