If you ask locals from Vis island which is the most visited attraction by tourists I’m pretty sure the answer will be the Blue Cave. Weather kept us from visiting it, so we had to make due with Green Cave, situated on the Ravnik island, south of Vis.
We’ve never been in a water cave, so it’s safe to say we were pretty amazed by the view once inside Green Cave (called Želena Spilja by the locals): a small opening in the ceiling of the cave lets the sun light pass through, creating an image very similar with a flashlight cone in the night. The cone is also visible in the water and you can clearly see the spot where it hits the seabed.
The cave is not accessible by land, thus you have to rent a boat to get there. We’ve traveled with a large group, so the cost of the trip was around 100 Croatian Kuna (around $18) for a boat owned by a friend of the guy where we stayed. The cost also included a trip to Stiniva Bay, a popular beach in VIS.
From what we’ve seen online, organized trips like this one will set you back a little bit more, but it’s worth it, if you ask me. Make sure you know how to swim, or you’ll have to ask someone with a smaller boat to take you inside the cave. Yes, that’s possible!
PS. Watch out for those people crazy enough to jump in the water from the top of the cave!