This natural sea cave on Biševo Island near Vis creates an ethereal blue glow when sunlight reflects through underwater opening onto white limestone floor. The magical 30-minute window between 11 AM-noon produces the most intense azure radiance.
The Blue Cave, known in Croatian as Modra špilja, is a small natural sea cave on the island of Biševo, approximately 5 kilometres southwest of the town of Komiža on Vis Island in the southern Dalmatian Adriatic. The cave is approximately 24 metres long, 12 metres wide, and 15 metres tall at its highest interior point, and was formed by wave action dissolving a sea-level karst chamber in the limestone cliff. Its defining phenomenon occurs when sunlight enters through a submerged arch in the cave's outer wall — approximately 2.5 metres below the water surface — and refracts upward through the crystal-clear water to illuminate the cave interior with an intense, shifting azure-blue light that reflects from the white limestone floor. The effect peaks between approximately 11 AM and noon, when the sun angle causes maximum light penetration through the underwater arch, turning the cave walls and water column a brilliant silver-blue. The cave is entered by small wooden rowing boats (no motors) through a low arch in the cliff face at sea level; passengers must duck as the boat passes through. The entire interior visit lasts approximately 10–15 minutes. Tours depart from Komiža on Vis in small motorboats, with passengers transferred into the rowing boats outside the cave. Sea conditions must be sufficiently calm for safe passage through the entrance arch — the cave is closed and tours cancelled when swell exceeds a moderate level. Combined boat excursions typically include the Green Cave on nearby Ravnik Island and a stop at Stiniva Cove.
Good to know
- Hours
- Tours run 9:00 AM - 4:00 PM (weather dependent)
- Best for
- photography, unique experiences, couples, nature lovers
Location
21485 Biševo
42.9797, 16.0408 View on map
Highlights
- Cave floor and water column illuminated in intense silver-blue from sunlight refracting through a submerged arch
- Peak blue glow between 11 AM and noon when sun angle maximises underwater light penetration
- Entry by wooden rowing boat through a low clifftop arch — the only vessel type permitted inside
- Interior ceiling and walls at 15 metres height producing an enclosed azure light effect unique in the Adriatic
- Combined boat tours from Komiža typically include Green Cave on Ravnik and Stiniva Cove
Tips for visiting
- Book tour from Vis, Hvar, or Split
- Best light 11 AM-noon
- Sea conditions must be calm
- Combined tours include Green Cave and Stiniva
When to visit
May through September for operational boat tours; June and September for calmer sea conditions that maximise tour completion rates. Aim for the 11 AM–noon window inside the cave for the strongest blue effect.
Accessibility
The Blue Cave is not accessible to wheelchair users or those with significant mobility limitations. Transferring between motorboat and rowing boat in open water, then ducking low through the cave arch, requires good mobility and balance. The cave visit is not recommended for visitors with claustrophobia as the entrance arch is very low.
Frequently asked questions
When is the best time to visit the Blue Cave?
The most intense blue colour is produced between 11 AM and noon when the sun is high enough for maximum light to penetrate the submerged arch. Morning tours depart Komiža from around 9 AM to position visitors at the cave entrance for the optimal window. Afternoon visits are still striking but the blue intensity reduces.
How long does the Blue Cave visit itself take?
The time inside the cave is approximately 10–15 minutes per group. The total excursion from Komiža including transfer by motorboat, transfer to rowing boat, the cave visit, and the return takes 2–3 hours. Combined tours to multiple caves and beaches extend to a half-day or full day.
Can the tour be cancelled?
The Blue Cave tour is cancelled when sea swell makes passage through the cave entrance arch unsafe. This can happen at short notice; cancellations are most common in late afternoon when afternoon wind picks up and after storm systems. Morning departures have the highest success rate in summer.