A 160m tunnel cave you swim into, ending at a hidden pebble beach in total darkness, named for the Mediterranean monk seal…A 160m tunnel cave you swim into, ending at a hidden pebble beach in total darkness, named for the Mediterranean monk seal, which bred here until the mid-20th century. Vast, silent and almost never visited, twenty minutes from the tour-boat queue at the Blue Cave. Monk seals, now among the rarest marine mammals on earth, with perhaps 700 left, used this cave as a pupping site within living memory. Croatian fishermen hunted them as competitors into the 20th century and the Adriatic population was lost. Occasional sightings still occur along this coast. Anchorage: Day visit by tender from Komiža or a Biševo anchorage; the outer coast has no shelter. Hazards: A long swim into a dark cave with no light at the far end, take a torch and never go alone. Any swell makes it dangerous. Plus