The Secret Behind the Blue Grotto in Capri

The Blue Grotto in Capri, Italy, is one of the world’s most enchanting spectacles. It’s no surprise that it’s probably the island’s most famous tourist attraction. It’s a stunning sea cave where the water glows with a brilliant blue color. But what lies behind this mesmerizing phenomenon that has inspired legends and captivated visitors for centuries? You’re about to find out. 

blue grotto blue waters

What is the Blue Grotto? 

The Blue Grotto is a natural cavity located along the northwestern coast of the island of Capri. It can be reached in various ways but entered only by small boats and once inside, you’ll be amazed by the magical atmosphere created by the unique feature that makes this place famous worldwide: the glowing blue color of the water.  

In photos, it looks like an artificial effect, something created with Photoshop. When you’re there and look at it with your own eyes, you might wonder if there are hidden lights underwater creating that incredible effect. But the magic of the Blue Grotto in Capri is entirely natural. Mother Nature brings this splendid, one-of-a-kind place to life, so beautiful that it almost seems too perfect to be real. 

why is the blue grotto is like that

Why is the Blue Grotto blue? 

If there’s no human intervention to create the spectacle of the Blue Grotto, how does it appear so blue? 

The phenomenon of the water’s coloration inside the Blue Grotto—where the water takes on intense blue tones, as if illuminated from below—is due to sunlight entering the grotto through an opening near its entrance. The light that penetrates is filtered by the water, which absorbs the red wavelengths and lets only the blue ones pass through. This is how the sea inside the grotto takes on the famous blue color that makes it so renowned. 

The Blue Grotto: one more secret 

There’s another phenomenon inside the Blue Grotto, one that’s usually not captured in photos and is known only to those who have visited: when an object is submerged in the waters of the Blue Grotto, it creates silvery reflections, as if something is magically illuminating it

This phenomenon is also entirely natural and is caused by air bubbles that form around the surface of objects. Since air has a different refractive index than water, these air bubbles allow light to escape, generating the stunning reflections described above. 

blue grotto effect

The History of the Blue Grotto 

In ancient times, the Blue Grotto was used as a marine nymphaeum by Emperor Tiberius, who had a villa built near the cavity. The grotto was adorned with works of art, and the sculptures found inside are now on display at the Casa Rossa in Anacapri

Over the centuries, however, the grotto became shrouded in legend and superstition, rumored to be a place haunted by spirits. This was likely due to the inability to attribute the phenomenon described above to natural causes, leading to beliefs in supernatural, malevolent interventions

It wasn’t until the 19th century—specifically in 1826—that a writer and a painter, accompanied by the sailor Angelo Ferraro, rediscovered the grotto and spread its fame worldwide. 

emperor tiberius

How to Reach the Blue Grotto 

No vacation to Capri or the Sorrento area is complete without a visit to the Blue Grotto. That’s why Iamme Ia! offers organized tours that include Capri and the Blue Grotto, providing you with a unique, stress-free experience. But how can you reach this sea cave? 

  • By boat: the entrance to the Blue Grotto can be reached by boat. Near the entrance, you’ll need to transfer from the main boat to one of the small rowing boats that are just the right size to enter the grotto. At the entrance, the boatman will ask all passengers to lie down while they guide the boat through the ropes installed along the coast. This is the only way the small boat can pass through the narrow opening and enter the grotto. 
  • By private transfer: Iamme Ia! organizes bus tours that lead you directly to the Blue Grotto, where you’ll have to take the small boat to enter the cave. It’s the most comfortable and easiest way to reach the place. 
  • On foot: for those who—for any reason—cannot or do not want to take a boat or bus, the Blue Grotto can also be reached on foot. From the center of Anacapri, you descend via Via Pagliaro and then Via Grotta Azzurra, before descending a staircase that leads to the sea. From there, if you want to enter the grotto, you have no other choice but to board one of the small boats and take the same route as described above, accompanied by an expert guide. 

The Blue Grotto in Capri is not just a natural wonder but a captivating blend of history, science, and myth. Don’t miss out: secure this wonderful experience with a click on Iamme Ia!

capri grotto entrance

Explore Sorrento and the Amalfi Coast with Iamme Ia! 

Who better to help you navigate this area than Iamme Ia! your expert companion. Connecting with us is easy. For more information on our tours, to make bookings, or to discuss your upcoming travel plans, please visit our tour pages or contact page on our website. 

If you find yourself wandering the charming streets of Sorrento, feel free to stop by our office at Piazza Torquato Tasso 16, where our friendly staff is eager to help you plan your next unforgettable adventure. As a proud Gray Line licensee, Iamme Ia! has been committed since 2014 to not only showcasing the stunning landscapes and rich culture of the Amalfi Coast but also to providing a narrative that weaves together breathtaking views, diverse experiences, and memorable moments.  

With Iamme Ia! your journey through Italy will be more than just a visit—it will be a profound engagement with the heart and soul of the region. Let us turn your trip into an experience of a lifetime.