Blue GrottoAbout Blue Grotto
The Blue Grotto (Modra špilja) is a sea cave on the eastern side of the island of Biševo, Croatia, notable for an intense blue light effect created when sunlight enters an underwater opening and illuminates the cave interior. It is one of the country’s best-known natural attractions.
Inside the cave, sunlight refracts through the water and bathes the interior in a vivid blue glow; the visual effect is dependent on sun angle and sea conditions. The cave is small and typically visited by guided small-boat tours that enter through a low aperture.
Local seafarers and islanders have long known the cave; it became widely known to tourists and naturalists in the late 19th and early 20th centuries and remains a managed visitor site. Boat operators run scheduled trips from nearby ports on Vis and Komiža.
The Blue Grotto sits on the east coast of Biševo island, reached by boat from the nearby islands of Vis and from the fishing village of Komiža.
- Best time to visit: The cave’s interior appears intensely blue when sunlight enters through a submerged opening and reflects off the water; the effect is strongest mid-morning, roughly between 11:00 and 13:00, depending on season.
- Access: Access is by small boats that enter through a low sea-level opening; boat crews often require passengers to sit low as they pass into the cave.
Nearby Attractions to Blue Grotto
Best Time to Visit Blue Grotto
Summer months offer best water clarity but also largest crowds; shoulder months are good for calmer conditions and fewer visitors.
Weather & Climate near Blue Grotto
Blue Grotto's climate is classified as Hot-Summer Mediterranean - Hot-Summer Mediterranean climate with hot summers (peaking in July) and cold winters (coldest in February). Temperatures range from 7°C to 29°C. Moderate rainfall (547 mm/year).
| Month | Comfort | Temp | Feels | Rain | Sky | Humidity | Wind | UV | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | Good | 7° - 12° | 8° | 53 mm | partly cloudy | 73% | 3.9 m/s | 0.2 low | 9.3h |
| February | Good | 7° - 12° | 7° | 43 mm | partly cloudy | 73% | 4.0 m/s | 0.4 low | 10.4h |
| March | Good | 8° - 14° | 11° | 48 mm | partly cloudy | 75% | 4.0 m/s | 0.7 moderate | 11.8h |
| April | Very Good | 11° - 17° | 14° | 42 mm | partly cloudy | 77% | 3.8 m/s | 1.1 high | 13.2h |
| May | Excellent | 15° - 22° | 18° | 36 mm | some cloud | 76% | 3.3 m/s | 1.6 very high | 14.4h |
| June | Ideal | 19° - 26° | 22° | 30 mm | mostly sunny | 73% | 3.0 m/s | 2.0 very high | 15.1h |
| July | Ideal | 21° - 29° | 25° | 18 mm | clear | 69% | 3.1 m/s | 2.1 extreme | 14.8h |
| August | Ideal | 21° - 29° | 25° | 32 mm | clear | 70% | 2.9 m/s | 1.7 very high | 13.7h |
| September | Excellent | 18° - 25° | 21° | 51 mm | some cloud | 70% | 3.3 m/s | 1.1 high | 12.3h |
| October | Very Good | 15° - 21° | 18° | 59 mm | partly cloudy | 73% | 3.5 m/s | 0.6 moderate | 10.9h |
| November | Good | 11° - 16° | 14° | 72 mm | partly cloudy | 74% | 4.3 m/s | 0.3 low | 9.6h |
| December | Good | 8° - 13° | 11° | 63 mm | partly cloudy | 72% | 4.1 m/s | 0.2 low | 9.0h |
How to Get to Blue Grotto
Boat trips depart from Komiža on the island of Vis or from the nearby island of Hvar; private boat charters from Split are also possible. Access depends on sea conditions and seasonal operator schedules.
Tips for Visiting Blue Grotto
- Go early in the morning straight to the Blue Grotto to avoid tour-boat rushes; light inside the cave is best around midday but crowds peak then.
- Bring biodegradable sunscreen - the grotto is sensitive and many operators request low-impact products.
- If prone to seasickness, take medication; the approach can be choppy in high winds.