People boat-visit mystery Blue Grotto in Croatia’s Bisevo

People take boats to visit the Blue Grotto (or the Blue Cave), a scenic spot in Croatia’s Bisevo, on July 19, 2021. The entrance of the cave is 1.6-meters-high and 2.5-meters-wide, whereas the inside reaches 12 meters deep and 15 meters high. The cave was formed by the sea waves.