Top 10 Captivating Facts About The Blue Grotto

It’s not hard to understand the attraction of a sea cave that contains water with a mesmerizing blue hue. What makes it even more special is that this particular cave was once used as a personal swimming spot for an infamous Roman Emperor in the 1st century A.D.

In this article, we’ll take a closer look at some of the most interesting facts about the Blue Grotto, a fascinating cave in southern Italy that has some interesting stories to tell.

1. It’s located on the coast of a famous Italian island

The Blue Grotto is a fascinating sea cave located in Anacapri, a village on the island of Capri in southern Italy.

The magnificent island is a popular tourist destination and is located just south of Naples and a few hundred kilometers southeast of Rome.

Capri is just a small, yet mountainous island as it only covers an area of 10.4 square kilometers (4.0 square miles). The mesmerizing sea cave can be found in the northeastern part of the island.

Island of Capri
View of the Island of Capri / Wiki Commons

2. The cave is pretty big but entering it is not as easy as it looks

It’s impossible to see the dimensions of the cave from the outside because its entrance is a very small arched opening. This makes it all the more surprising that the interior of the cave is actually quite big.

The cave has a length of about 60 meters (196 feet) and a maximum width of 25 meters (82 feet). At the end of the cave, there are also several passageways going even deeper into the rock formation of the Capri coastline.

3 of these passageways lead you to a room referred to as the “Sala dei Nomi” which translates to the “Room of Names.” This space is called this way because of the visitors that have left their signature on its walls over the centuries.

2 more passageways lead even deeper into the cliffs until they reach a dead end.

3. The entrance is not the main source of light inside the cave

So what causes the water inside the Blue Grotto to produce such a fascinating emerald color?

The answer is simply the fact that the conditions inside the cave are perfect to produce this type of hue. The combination of the small light sources and the large interior result in one of the most astounding natural wonders you’ll ever come across.

We do mention light sources because apart from the visible opening through which you can enter the cave, there’s another one as well.

Right below this arched entrance, there’s another hole, about 10 times the size of the visible one. Even though it doesn’t appear to be the case initially, this is actually the main light source inside the cave.

This large opening inside the rocks allows red colors to be filtered out as the light passes through the water. This is the main reason why the water is so deep blue inside the cave.

Blue grotto facts
View inside the cave / Glen Scarborough /

4. A Roman Emperor once decorated the cave with sculptures

The second Roman Emperor was a man named Tiberius, the stepson of the man who all started it, the first Roman Emperor Augustus. He reigned from 14-37 A.D. and made a remarkable move in the year 26 A.D.

This was the year when Tiberius moved from Rome to the Island of Capri. The island was already a popular resort during the Roman Republic era, but regardless of this notion, this move was quite surprising.

He built himself a villa on the island called the “Villa Jovis,” a mansion completed in 27 A.D. of which the remains can still be visited.

Apart from his own villa, Tiberius used the Blue Grotto as his own pleasure hole whenever he wanted to go for a swim. To make the environment even better, he had the cave decorated with several statues, including the Roman sea gods Neptune and Triton, and a resting place around the edge.

5. The Grotto Azzura can be visited when the conditions are suited

Visiting the Grotta Azzura is possible as there are several tours available on the island. One starts in the village of Anacapri itself, or you can take a boat from the main port on the island called Marina Grande.

This doesn’t mean, however, that visiting the cave is possible at all times. It needs to be low tide and the sea needs to be calm. Otherwise, entering the cave is simply not possible because the arched entranceway is too small.

Regardless, visiting this magnificent natural miracle is simply a must in case you plan to stay in Capri.

Blue Grotto Inside
Inside the amazing cave / Colling-architektur /

More interesting facts about the Blue Grotto

6. Even though it’s possible to enter the cave at low tide and when the sea is calm, it’s not as easy as it looks. It’s only possible to enter the cave in a small rowboat suitable for just 4 people.

While passing the entranceway, all visitors must lie flat on the bottom of this small boat, including the experienced oarsman. He will use chains attached to the cave to pull the boat inside, quite a complicated endeavor indeed.

7. Apart from the magnificent blue emerald color of the water, another special effect is created inside the cave. Everything inside the water appears to be silver, remarkably produced by tiny bubbles that cover the object inside the water.

8. We know that the cave was decorated with statues of Roman because 3 of them were actually recovered from the cave’s floor. These statues of Neptune and Triton are now on display in a museum in the village of Anacapri.

We’re pretty sure there are still some lying down there because an investigation in 2009 has resulted in 7 bases of statues being recovered. This means that the cave was pretty much a sanctuary of Roman Emperor Tiberius during his stay in Capri.

Grotta Azzura Facts
The mysterious cave / Michael Costa /

9. Even though the statue of Triton that was recovered is missing its arms, it was already described in the 1st century A.D. by early Roman Empire historian Pliny the Elder.

He mentioned that Triton was depicted while he was playing on a shell, a common theme of this particular Roman god. This means that both the arm he used to play with and the shell are probably still residing on the cave’s floor today.

10. Nobody visited the cave during the 18th century because the people living on Capri believed that it was inhabited by witches and other horrible creatures. The cave was known as “Gradola” back then, a reference to the nearby landing place for boats.

It wasn’t until the year 1826 that tourists dared to enter the cave again, something pioneered by German writer and poet August Kopisch and his friend, painter Ernst Fries.

Since then, the captivating cave has been one of the most popular attractions on the wonderful island of Capri.

Blue Grotto Painting 1836
Painting of the discover by Jakob Alt (1836) / Wiki Commons