Blue Below

This is the Blue Grotto (aka Blue Cave, Modra špilja) located in a small bay named Balun, on the island of Biševo in the Croatian Adriatic in Croatia.   Until 1884, this cave was only accessible by diving, however today artificially created entrance allows for small boats and tourists to enter and enjoy.   Between 11 a.m and 12 noon daily (and seasonally), sunlight reflects through the water coming from the white floor of the cave and bathes the grotto in aquamarine light, while objects in the water appear to be silver.  The cater is almost 80 feet in length and over 30 feet in depth.  It receives about 10,000 visitors annually.