The Blue Cave (Modra špilja) on the island of Bisevo is one of the most beautiful secrets of the Adriatic sea. The ideal moment to visit the cave is between 11 a.m. and noon. At this time of day, the sunlight reflects through the water coming from the white floor of the cave and colours it in blue light, while objects in the water appear to be silver.
Although it’s sometimes possible to visit the cave out of season, the sea conditions from October to May usually make entry into the cave impossible. So the best time to visit is June-September. You can visit the cave on a boat, but diving or snorkeling in the Blue Cave is worth trying to fully appreciate its beauty.