Blue Cave

The Blue Grotto or Blue Cave (Croatian: Modra pilja) is a waterlogged sea cave on the east side of the island of Bievo, about 4.5 nautical miles (8.3 kilometers) from Komia in the Croatian Adriatic. It is located 5 kilometers south-west of the island of Vis in the middle Dalmatian archipelago. Because of the dazzling blue light that shines at certain times of day, the grotto is one of the most well-known natural beauty locations on the Adriatic and one of the most beautiful caves in Croatia. The cave was once only accessible by diving because it had one natural entrance below sea level, as reported and illustrated by Baron Eugen von Ransonet. Based on his suggestion, an artificial entrance large enough for small boats was built in 1884.

The cave's natural entrance, positioned on its southern side, is supposed to resemble a grotto's vaulted ceiling. The sunlight enters the cave through this submarine-like entrance in the cave roof, creating an iridescent blue glowing effect all throughout the cave. In addition, a stone bar linking two cave walls is plainly visible just below the waterline in both above-water and underwater shots.

The best time to visit the cave is between 11 a.m. and 12 p.m., depending on the season. The sunshine reflects through the water flowing from the cave's white bottom, bathing the grotto in aquamarine light and making everything in the water appear silver. This type of occurrence is also known at the Blue Grotto (Italian: Grotta Azzurra) on the Italian island of Capri.

Every year, around 10,000 tourists visit the cave, and tourist boats frequently include a visit to another comparable cave on the island, the Zelena pilja (English: The Green Grotto), which is larger and has an emerald-green tone due to a similar effect.