My first time swimming in Croatia's Blue Caves

I'd seen photos of the Adriatic's blue caves dozens of times before going — it's one of the most photographed stops on any island tour out of Dubrovnik, almost a cliché by now. Nothing prepared me for the exact moment the boat slips through the cave's narrow mouth and the water suddenly starts glowing an electric blue that doesn't look real.

The 3-island tour brought us there mid-morning, with the sun still relatively low — the right angle, our guide explained with obvious pride, for the light to enter from below the water and bounce back up, creating that particular effect.

We got in and started swimming straight from the boat, without thinking too much about it, and underwater the effect multiplied even more: your whole body, your hands, the entire surface looked lit from within, like swimming inside a blue lightbulb.

There's nothing to distract you from the color of the water, which is, without exaggeration, the main element of the whole experience. Everything else fades into the background.

It's not a large cave, and honestly not especially spectacular architecturally — it's small, almost intimate, with room for only a few boats at once. But of all the stops that day, the blue caves were, without a doubt, the moment that stuck with us the most.

How to do the 3-island tour

The tour leaves from Dubrovnik's harbor and in a single day brings together blue caves, hidden beaches and small villages only reachable by boat. It's the day that best sums up why the Adriatic has a reputation as one of Europe's most beautiful seas. Always carry cash and sunscreen, because many stops have neither an ATM nor shade.

If you'd prefer something calmer, Lokrum is only 15 minutes away. And for caves and coves off the tour circuit, Betina Cave Beach is a hidden cove with caves that you can only reach by boat or kayak. The beaches in the area have no sand, so bring water shoes.

To choose a date, see the best time to visit Croatia, and to organize the rest, our 7-day Croatia itinerary.